TPM1 (Tropomyosin 1) is a coiled-coil actin-binding protein with 10 tissue-specific isoforms. ISOFORM BIOLOGY: (1) Isoform 1 (TPM1alpha, P09493-1) is expressed in SKELETAL MUSCLE; (2) Isoform 2 is SMOOTH MUSCLE-specific; (3) Isoform 3 (TM3) is the FIBROBLAST/cytoskeletal form; (4) Isoform 6 (TPM1kappa) is CARDIAC-specific. UniProt states "Isoform 1 is expressed in adult and fetal skeletal muscle and cardiac tissues. Isoform 10 is expressed in adult and fetal cardiac tissues, but not in skeletal muscle." Muscle isoforms regulate actin-myosin interaction in sarcomeres; cytoskeletal isoforms organize non-muscle actin. DISEASE: Mutations cause cardiomyopathy (CMH3, CMD1Y) affecting sarcomere function. Annotations for "muscle contraction" and "sarcomere" apply primarily to muscle isoforms, while "cytoskeleton organization" applies more to non-muscle isoforms.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
|
GO:0051015
actin filament binding
|
IBA
GO_REF:0000033 |
ACCEPT |
Summary: Core function of all TPM1 isoforms. Tropomyosin binds along the length of actin filaments in both muscle and non-muscle cells. UniProt states that TPM1 binds to actin filaments. This function is conserved across all isoforms - muscle isoforms bind thin filament actin while cytoskeletal isoforms bind stress fiber actin.
Reason: Actin filament binding is the fundamental molecular function of all tropomyosins. IBA annotation is appropriate as this function is phylogenetically conserved. Supported by functional studies showing TPM1 binds actin filaments in both muscle and non-muscle contexts [PMID:12686598].
Supporting Evidence:
PMID:12686598
tropomyosin-1 was found diffuse in the cells, whereas it quickly colocalized with actin and stress fibers upon stimulation
PMID:8205619
alpha-tropomyosin and cardiac troponin T as well as beta myosin heavy chain mutations cause the same phenotype, we conclude that FHC is a disease of the sarcomere
|
|
GO:0007015
actin filament organization
|
IBA
GO_REF:0000033 |
ACCEPT |
Summary: TPM1 plays a role in actin filament organization in both muscle and non-muscle cells. In muscle, it organizes thin filaments; in non-muscle cells, it contributes to stress fiber formation and cytoskeletal organization [PMID:12686598].
Reason: Actin filament organization is a core function of tropomyosins across all isoforms. Muscle isoforms organize thin filaments in sarcomeres; cytoskeletal isoforms stabilize stress fibers in non-muscle cells. IBA annotation is appropriate.
Supporting Evidence:
PMID:12686598
phosphorylation of tropomyosin-1 downstream of ERK by contributing to formation of actin filaments increases cellular contractility and promotes the formation of focal adhesions
PMID:15897890
TGF-beta induction of stress fibers in epithelial cells requires high molecular weight tropomyosins encoded by TPM1 and TPM2 genes
|
|
GO:0005884
actin filament
|
IBA
GO_REF:0000033 |
ACCEPT |
Summary: TPM1 localizes to actin filaments in both muscle and non-muscle cells. This cellular component annotation reflects the physical location of tropomyosin bound along actin filaments.
Reason: Tropomyosin is an integral component of actin filaments. In muscle cells it forms the thin filament regulatory complex; in non-muscle cells it associates with stress fibers and other actin structures. IBA annotation is appropriate.
Supporting Evidence:
PMID:12686598
tropomyosin-1 was found diffuse in the cells, whereas it quickly colocalized with actin and stress fibers upon stimulation
|
|
GO:0060048
cardiac muscle contraction
|
IBA
GO_REF:0000033 |
ACCEPT |
Summary: ISOFORM-SPECIFIC: Cardiac muscle contraction is a function of the striated muscle isoforms (Isoform 1/TPM1alpha and Isoform 6/TPM1kappa). UniProt states Isoform 1 is expressed in cardiac tissues and Isoform 6 is cardiac-specific. Mutations cause cardiomyopathy (CMH3, CMD1Y) [PMID:8205619, PMID:11273725].
Reason: This is a core function for cardiac isoforms. TPM1 plays a central role in calcium-dependent regulation of cardiac muscle contraction via the troponin complex. Mutations affecting this function cause hypertrophic and dilated cardiomyopathy, demonstrating its importance [PMID:8205619]. IBA annotation is appropriate as this function is conserved in striated muscle isoforms.
Supporting Evidence:
PMID:8205619
We demonstrate that missense mutations (Asp175Asn; Glu180Gly) in the alpha-tropomyosin gene cause familial hypertrophic cardiomyopathy (FHC)
PMID:11136687
HCM was linked to the TPM1 gene... The mutation caused a 40% to 50% increase in calcium affinity in regulated thin filament-myosin subfragment-1 (S1) MgATPase assays
|
|
GO:0003779
actin binding
|
IEA
GO_REF:0000043 |
ACCEPT |
Summary: Actin binding is the fundamental molecular function of all tropomyosins. This IEA annotation based on UniProt keyword mapping is correct but less specific than GO:0051015 (actin filament binding) which is already annotated via IBA.
Reason: While this is a broader parent term of actin filament binding, it is still correct. IEA annotations at a broader level are acceptable alongside more specific experimental annotations. No action needed as the more specific IBA annotation (GO:0051015) captures the precise function.
Supporting Evidence:
PMID:12686598
tropomyosin-1 was found diffuse in the cells, whereas it quickly colocalized with actin and stress fibers upon stimulation
|
|
GO:0005856
cytoskeleton
|
IEA
GO_REF:0000044 |
ACCEPT |
Summary: TPM1 is a cytoskeletal protein. UniProt subcellular location indicates "Cytoplasm, cytoskeleton" and notes it "Associates with F-actin stress fibers." This is a broad cellular component annotation appropriate for all isoforms.
Reason: This is a valid broad localization term. All TPM1 isoforms are components of the cytoskeleton, whether in sarcomeres (muscle isoforms) or stress fibers (non-muscle isoforms). IEA based on UniProt subcellular location is appropriate.
Supporting Evidence:
PMID:12686598
tropomyosin-1 was found diffuse in the cells, whereas it quickly colocalized with actin and stress fibers upon stimulation
|
|
GO:0005862
muscle thin filament tropomyosin
|
IEA
GO_REF:0000117 |
ACCEPT |
Summary: ISOFORM-SPECIFIC: This cellular component term is specifically for muscle isoforms (Isoform 1/skeletal, Isoform 2/smooth, Isoform 6/cardiac). The muscle thin filament tropomyosin complex contains tropomyosin bound to actin filaments in sarcomeres. Non-muscle isoforms (e.g., Isoform 3/fibroblast) do not form this specific complex.
Reason: This is a core localization for muscle isoforms of TPM1. The annotation is correct for the muscle-expressed isoforms that are integral to the thin filament regulatory complex in sarcomeres [PMID:8205619].
Supporting Evidence:
PMID:8205619
FHC is a disease of the sarcomere
PMID:11136687
regulated thin filament-myosin subfragment-1 (S1) MgATPase assays
|
|
GO:0005515
protein binding
|
IPI
PMID:16189514 Towards a proteome-scale map of the human protein-protein in... |
MARK AS OVER ANNOTATED |
Summary: High-throughput Y2H interactome study. The term "protein binding" is uninformative and does not indicate specific binding partners or functional context. TPM1 binds actin, troponins, and other muscle/cytoskeletal proteins, but this generic term does not capture those specific interactions.
Reason: "Protein binding" (GO:0005515) is an uninformative annotation that does not convey the specific molecular interactions of TPM1 (e.g., actin binding, troponin complex binding). High-throughput interactome studies often generate these generic annotations. More specific MF terms are preferred [PMID:16189514].
Supporting Evidence:
PMID:16189514
Using a stringent, high-throughput yeast two-hybrid system, we tested pairwise interactions among the products of approximately 8,100 currently available Gateway-cloned open reading frames and detected approximately 2,800 interactions
|
|
GO:0005515
protein binding
|
IPI
PMID:21516116 Next-generation sequencing to generate interactome datasets. |
MARK AS OVER ANNOTATED |
Summary: High-throughput Stitch-seq Y2H interactome study. The generic term "protein binding" is uninformative for this well-characterized actin-binding protein.
Reason: "Protein binding" (GO:0005515) from high-throughput interactome studies is too generic. TPM1 has specific, well-characterized binding partners (actin, troponins, LMOD2, TMOD1) that are more informative [PMID:21516116].
Supporting Evidence:
PMID:21516116
We describe a massively parallel interactome-mapping pipeline, Stitch-seq, that combines PCR stitching with next-generation sequencing and used it to generate a new human interactome dataset
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GO:0005515
protein binding
|
IPI
PMID:25416956 A proteome-scale map of the human interactome network. |
MARK AS OVER ANNOTATED |
Summary: Large-scale proteome-scale human interactome map study. Generic "protein binding" term is uninformative for TPM1 which has well-characterized specific interactions.
Reason: "Protein binding" (GO:0005515) from systematic interactome mapping is too generic. TPM1 has specific, functionally important binding partners that should be annotated instead [PMID:25416956].
Supporting Evidence:
PMID:25416956
Here, we describe a systematic map of ?14,000 high-quality human binary protein-protein interactions
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GO:0005515
protein binding
|
IPI
PMID:26871637 Widespread Expansion of Protein Interaction Capabilities by ... |
MARK AS OVER ANNOTATED |
Summary: Study on alternative splicing and protein interaction capabilities. Notably relevant for TPM1 which has 10 isoforms with different interaction profiles. However "protein binding" remains uninformative.
Reason: While this study is highly relevant to TPM1 isoform biology, showing that alternative isoforms exhibit different interaction profiles, the generic "protein binding" term does not capture the specific binding partners or isoform-specific interactions [PMID:26871637].
Supporting Evidence:
PMID:26871637
The majority of isoform pairs share less than 50% of their interactions. In the global context of interactome network maps, alternative isoforms tend to behave like distinct proteins rather than minor variants of each other
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|
GO:0005515
protein binding
|
IPI
PMID:30021884 Histone Interaction Landscapes Visualized by Crosslinking Ma... |
MARK AS OVER ANNOTATED |
Summary: Crosslinking mass spectrometry study of histone interactions in nuclei. TPM1 is a cytoplasmic/cytoskeletal protein; its detection here may be incidental. Generic "protein binding" term is uninformative.
Reason: "Protein binding" from crosslinking MS study of nuclear proteins is not informative for TPM1, which is primarily a cytoskeletal protein. The generic term provides no functional insight [PMID:30021884].
Supporting Evidence:
PMID:30021884
Here we use crosslinking mass spectrometry (XL-MS) to chart the protein-protein interactions in intact human nuclei
|
|
GO:0005515
protein binding
|
IPI
PMID:33961781 Dual proteome-scale networks reveal cell-specific remodeling... |
MARK AS OVER ANNOTATED |
Summary: BioPlex 3.0 dual proteome-scale network study in 293T and HCT116 cells. While this reveals cell-specific interactome remodeling relevant to TPM1 isoforms, the generic "protein binding" term is uninformative.
Reason: "Protein binding" from large-scale AP-MS interactome study does not provide specific information about TPM1's functional binding partners. More specific terms for actin binding, troponin binding etc. are preferred [PMID:33961781].
Supporting Evidence:
PMID:33961781
Thousands of interactions assemble proteins into modules that impart spatial and functional organization to the cellular proteome
|
|
GO:0005515
protein binding
|
IPI
PMID:40205054 Multimodal cell maps as a foundation for structural and func... |
MARK AS OVER ANNOTATED |
Summary: Multimodal cell maps study integrating multiple data types for structural and functional genomics. Generic "protein binding" term is uninformative.
Reason: "Protein binding" from multimodal cell mapping study does not convey specific information about TPM1's well-characterized binding partners [PMID:40205054].
Supporting Evidence:
PMID:40205054
Multimodal cell maps as a foundation for structural and functional genomics
|
|
GO:0005515
protein binding
|
IPI
P09493-10 PMID:25910212 Widespread macromolecular interaction perturbations in human... |
MARK AS OVER ANNOTATED |
Summary: ISOFORM-SPECIFIC ANNOTATION (P09493-10). Study on macromolecular interaction perturbations in genetic disorders. While highly relevant to understanding how TPM1 mutations affect interactions, "protein binding" is uninformative.
Reason: "Protein binding" from edgetic mutation studies is too generic. This study shows disease mutations can perturb specific interactions, but the annotation lacks specificity about which interactions [PMID:25910212].
Supporting Evidence:
PMID:25910212
While common variants from healthy individuals rarely affect interactions, two-thirds of disease-associated alleles perturb protein-protein interactions, with half corresponding to "edgetic" alleles affecting only a subset of interactions while leaving most other interactions unperturbed
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GO:0005515
protein binding
|
IPI
P09493-10 PMID:32296183 A reference map of the human binary protein interactome. |
MARK AS OVER ANNOTATED |
Summary: ISOFORM-SPECIFIC ANNOTATION (P09493-10). HuRI reference human binary protein interactome map. While highly valuable for mapping interactions, the generic "protein binding" term is uninformative for TPM1.
Reason: "Protein binding" from the comprehensive HuRI interactome map does not convey specific binding partners. TPM1 has well-characterized interactions with actin, troponins, and other thin filament proteins that are more informative [PMID:32296183].
Supporting Evidence:
PMID:32296183
Here we present a human 'all-by-all' reference interactome map of human binary protein interactions, or 'HuRI'
|
|
GO:0042802
identical protein binding
|
ISS
GO_REF:0000024 |
ACCEPT |
Summary: Tropomyosins form coiled-coil dimers (homo- or heterodimers) as their functional unit. UniProt indicates TPM1 forms dimers with itself or other tropomyosin isoforms. This ISS annotation from sequence similarity is consistent with the coiled-coil structure of tropomyosins.
Reason: TPM1 forms parallel coiled-coil dimers that bind along actin filaments. This is a fundamental structural property of all tropomyosins. Self-association (homodimerization) is documented in UniProt. ISS annotation based on sequence similarity to characterized orthologs is appropriate.
|
|
GO:0042803
protein homodimerization activity
|
ISS
GO_REF:0000024 |
ACCEPT |
Summary: Tropomyosins function as coiled-coil dimers. TPM1 homodimerizes to form the functional unit that binds along actin filaments. This is a core structural property of tropomyosins.
Reason: Homodimerization is fundamental to tropomyosin function. Two TPM1 chains form a parallel coiled-coil dimer that spans seven actin subunits. ISS annotation based on sequence similarity is appropriate for this conserved structural property.
|
|
GO:0046982
protein heterodimerization activity
|
ISS
GO_REF:0000024 |
ACCEPT |
Summary: TPM1 can form heterodimers with other tropomyosin isoforms (e.g., TPM2, TPM3). UniProt indicates it interacts with self or TPM2. Heterodimer formation provides functional diversity in different tissue contexts.
Reason: Heterodimerization with other tropomyosin isoforms is a documented property that provides functional diversity. TPM1 can form dimers with TPM2 and potentially other isoforms. ISS annotation based on sequence similarity is appropriate.
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|
GO:0051015
actin filament binding
|
ISS
GO_REF:0000024 |
ACCEPT |
Summary: Duplicate of the IBA annotation for actin filament binding. This ISS annotation provides additional evidence for this core function from sequence similarity.
Reason: Actin filament binding is the fundamental molecular function of TPM1 across all isoforms. This ISS annotation supplements the IBA annotation and is consistent with the conserved function of tropomyosins.
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|
GO:0008360
regulation of cell shape
|
IMP
PMID:21817107 MicroRNA-21 regulates vascular smooth muscle cell function v... |
KEEP AS NON CORE |
Summary: ISOFORM-SPECIFIC: This annotation relates to the cytoskeletal (non-muscle) function of TPM1 isoforms. The study shows TPM1 affects vascular smooth muscle cell morphology via cytoskeletal remodeling [PMID:21817107].
Reason: Regulation of cell shape is a function of cytoskeletal TPM1 isoforms in non-muscle cells. While important, it is not the core function of the striated muscle isoforms. This is a valid annotation for cytoskeletal isoforms [PMID:21817107].
Supporting Evidence:
PMID:21817107
cell proliferation and migration were significantly decreased by
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GO:1904706
negative regulation of vascular associated smooth muscle cell proliferation
|
IMP
PMID:21817107 MicroRNA-21 regulates vascular smooth muscle cell function v... |
KEEP AS NON CORE |
Summary: ISOFORM-SPECIFIC: TPM1 overexpression inhibits vascular smooth muscle cell (VSMC) proliferation. This relates to the cytoskeletal function of TPM1 in regulating cell behavior [PMID:21817107].
Reason: This is a valid functional annotation for cytoskeletal TPM1 isoforms in smooth muscle cells. While biologically relevant, it represents a peripheral function rather than the core sarcomeric function of TPM1 [PMID:21817107].
Supporting Evidence:
PMID:21817107
cell proliferation and migration were significantly decreased by
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GO:1904753
negative regulation of vascular associated smooth muscle cell migration
|
IMP
PMID:21817107 MicroRNA-21 regulates vascular smooth muscle cell function v... |
KEEP AS NON CORE |
Summary: ISOFORM-SPECIFIC: TPM1 overexpression inhibits vascular smooth muscle cell (VSMC) migration. This relates to the cytoskeletal function of TPM1 in regulating cell motility [PMID:21817107].
Reason: This is a valid functional annotation for cytoskeletal TPM1 isoforms in smooth muscle cells. While biologically relevant, it represents a peripheral function rather than the core sarcomeric function of TPM1 [PMID:21817107].
Supporting Evidence:
PMID:21817107
cell proliferation and migration were significantly decreased by
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GO:0005829
cytosol
|
TAS
Reactome:R-HSA-390593 |
ACCEPT |
Summary: Reactome pathway annotation for muscle contraction. TPM1 is a cytosolic/ cytoskeletal protein that associates with actin filaments. Cytosol localization is valid for soluble tropomyosin before assembly.
Reason: Cytosol is an appropriate cellular component for TPM1. Prior to incorporation into actin filaments, tropomyosin exists in the cytosol. Reactome pathway annotations for muscle contraction support this localization.
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GO:0005829
cytosol
|
TAS
Reactome:R-HSA-390595 |
ACCEPT |
Summary: Duplicate Reactome pathway annotation for cytosol localization in muscle contraction pathway.
Reason: Valid cellular component annotation from Reactome muscle contraction pathway. Cytosol localization is appropriate for soluble tropomyosin.
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GO:0005829
cytosol
|
TAS
Reactome:R-HSA-390597 |
ACCEPT |
Summary: Duplicate Reactome pathway annotation for cytosol localization.
Reason: Valid cellular component annotation from Reactome pathway. Cytosol localization is appropriate for soluble tropomyosin.
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GO:0005829
cytosol
|
TAS
Reactome:R-HSA-390598 |
ACCEPT |
Summary: Duplicate Reactome pathway annotation for cytosol localization.
Reason: Valid cellular component annotation from Reactome pathway. Cytosol localization is appropriate for soluble tropomyosin.
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GO:0005829
cytosol
|
TAS
Reactome:R-HSA-445699 |
ACCEPT |
Summary: Duplicate Reactome pathway annotation for cytosol localization.
Reason: Valid cellular component annotation from Reactome pathway. Cytosol localization is appropriate for soluble tropomyosin.
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GO:0005829
cytosol
|
TAS
Reactome:R-HSA-445700 |
ACCEPT |
Summary: Duplicate Reactome pathway annotation for cytosol localization.
Reason: Valid cellular component annotation from Reactome pathway. Cytosol localization is appropriate for soluble tropomyosin.
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GO:0005829
cytosol
|
TAS
Reactome:R-HSA-445704 |
ACCEPT |
Summary: Duplicate Reactome pathway annotation for cytosol localization.
Reason: Valid cellular component annotation from Reactome pathway. Cytosol localization is appropriate for soluble tropomyosin.
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GO:0005829
cytosol
|
TAS
Reactome:R-HSA-445705 |
ACCEPT |
Summary: Duplicate Reactome pathway annotation for cytosol localization.
Reason: Valid cellular component annotation from Reactome pathway. Cytosol localization is appropriate for soluble tropomyosin.
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GO:0008092
cytoskeletal protein binding
|
IPI
PMID:17987659 Nebulette interacts with filamin C. |
ACCEPT |
Summary: TPM1 binds cytoskeletal proteins including nebulette. The study identified tropomyosin-1 as a binding partner of nebulette in a yeast two-hybrid screen [PMID:17987659].
Reason: Cytoskeletal protein binding accurately describes TPM1's interactions with actin filaments and associated regulatory proteins. This is a valid molecular function annotation that is more specific than "protein binding".
Supporting Evidence:
PMID:17987659
Nebulette interacts with filamin C.
|
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GO:0045214
sarcomere organization
|
IMP
PMID:11273725 Mutations that alter the surface charge of alpha-tropomyosin... |
ACCEPT |
Summary: ISOFORM-SPECIFIC: Sarcomere organization is a function of muscle isoforms. TPM1 mutations cause disorganized sarcomere structure in cardiomyopathy [PMID:11273725].
Reason: Sarcomere organization is a core function of striated muscle TPM1 isoforms. Mutations affecting this function cause hypertrophic and dilated cardiomyopathy. This is a well-supported experimental annotation [PMID:11273725].
Supporting Evidence:
PMID:11273725
Proteins in cardiac myocytes assemble into contractile units known as sarcomeres
|
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GO:0001725
stress fiber
|
IDA
PMID:12686598 Extracellular signal-regulated kinase mediates phosphorylati... |
ACCEPT |
Summary: ISOFORM-SPECIFIC: TPM1 localizes to stress fibers in non-muscle cells. The study shows TPM1 colocalizes with actin stress fibers upon stimulation [PMID:12686598].
Reason: Stress fiber localization is a valid cellular component annotation for cytoskeletal TPM1 isoforms (e.g., Isoform 3/TM3). IDA evidence from direct observation of colocalization with stress fibers [PMID:12686598].
Supporting Evidence:
PMID:12686598
tropomyosin-1 was found diffuse in the cells, whereas it quickly colocalized with actin and stress fibers upon stimulation
|
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GO:0003065
positive regulation of heart rate by epinephrine
|
ISS
PMID:17556658 Dilated cardiomyopathy mutant tropomyosin mice develop cardi... |
KEEP AS NON CORE |
Summary: ISOFORM-SPECIFIC: This relates to cardiac isoforms (TPM1alpha, TPM1kappa) and their role in beta-adrenergic signaling in the heart. Tropomyosin phosphorylation modulates cardiac contractility.
Reason: While TPM1 is involved in cardiac muscle contraction, the specific role in epinephrine-mediated heart rate regulation is indirect via modulation of thin filament Ca2+ sensitivity. This is a secondary function rather than a core molecular function.
Supporting Evidence:
PMID:17556658
2007 Jun 7. Dilated cardiomyopathy mutant tropomyosin mice develop cardiac dysfunction with significantly decreased fractional shortening and myofilament calcium sensitivity.
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GO:0003779
actin binding
|
TAS
PMID:12686598 Extracellular signal-regulated kinase mediates phosphorylati... |
ACCEPT |
Summary: Core function of TPM1. Actin binding is fundamental to all TPM1 isoforms. This TAS annotation based on literature review is consistent with the well-established role of tropomyosin [PMID:12686598].
Reason: Actin binding is the fundamental molecular function of tropomyosin. This annotation supplements the more specific "actin filament binding" term already annotated via IBA [PMID:12686598].
Supporting Evidence:
PMID:12686598
tropomyosin-1 was found diffuse in the cells, whereas it quickly colocalized with actin and stress fibers upon stimulation
|
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GO:0005200
structural constituent of cytoskeleton
|
TAS
PMID:12686598 Extracellular signal-regulated kinase mediates phosphorylati... |
ACCEPT |
Summary: TPM1 is a structural component of the actin cytoskeleton in both muscle and non-muscle cells. In muscle cells it forms thin filaments; in non-muscle cells it stabilizes stress fibers [PMID:12686598].
Reason: Structural constituent of cytoskeleton is an accurate molecular function for TPM1. Tropomyosin provides structural stability to actin filaments and is integral to cytoskeletal architecture [PMID:12686598].
Supporting Evidence:
PMID:12686598
phosphorylation of tropomyosin-1 downstream of ERK by contributing to formation of actin filaments increases cellular contractility and promotes the formation of focal adhesions
|
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GO:0007010
cytoskeleton organization
|
TAS
PMID:12686598 Extracellular signal-regulated kinase mediates phosphorylati... |
ACCEPT |
Summary: TPM1 contributes to cytoskeleton organization in both muscle and non-muscle cells. This is closely related to actin filament organization [PMID:12686598].
Reason: Cytoskeleton organization is a core function of TPM1 across all isoforms. In muscle, it organizes sarcomere thin filaments; in non-muscle cells, it contributes to stress fiber organization [PMID:12686598].
Supporting Evidence:
PMID:12686598
phosphorylation of tropomyosin-1 downstream of ERK by contributing to formation of actin filaments increases cellular contractility and promotes the formation of focal adhesions
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GO:0030049
muscle filament sliding
|
ISS
PMID:11136687 Hypertrophic cardiomyopathy caused by a novel alpha-tropomyo... |
ACCEPT |
Summary: ISOFORM-SPECIFIC: Muscle filament sliding is a function of striated muscle isoforms. TPM1 regulates the interaction between thin and thick filaments during muscle contraction [PMID:11136687].
Reason: Muscle filament sliding is a core function of muscle TPM1 isoforms. Tropomyosin regulates the actin-myosin interaction that drives filament sliding during contraction. Mutations affecting this cause cardiomyopathy [PMID:11136687].
Supporting Evidence:
PMID:11136687
The mutation caused a 40% to 50% increase in calcium affinity in regulated thin filament-myosin subfragment-1 (S1) MgATPase assays
|
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GO:0030336
negative regulation of cell migration
|
ISS
PMID:15897890 Silencing of the Tropomyosin-1 gene by DNA methylation alter... |
KEEP AS NON CORE |
Summary: ISOFORM-SPECIFIC: Cytoskeletal TPM1 isoforms regulate cell migration. High molecular weight tropomyosins stabilize stress fibers and inhibit cell motility [PMID:15897890].
Reason: Regulation of cell migration is a function of cytoskeletal TPM1 isoforms in non-muscle cells. While valid, this is a peripheral function related to the core actin-binding activity [PMID:15897890].
Supporting Evidence:
PMID:15897890
TGF-beta induction of stress fibers in epithelial cells requires high molecular weight tropomyosins encoded by TPM1 and TPM2 genes
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GO:0031529
ruffle organization
|
ISS
PMID:15897890 Silencing of the Tropomyosin-1 gene by DNA methylation alter... |
KEEP AS NON CORE |
Summary: ISOFORM-SPECIFIC: TPM1 affects membrane ruffle organization in non-muscle cells. This relates to cytoskeletal actin dynamics [PMID:15897890].
Reason: Ruffle organization is a function of cytoskeletal TPM1 isoforms in non-muscle cells. This is a peripheral function related to the core actin-organizing activity [PMID:15897890].
Supporting Evidence:
PMID:15897890
TGF-beta induction of stress fibers in epithelial cells requires high molecular weight tropomyosins encoded by TPM1 and TPM2 genes
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GO:0032059
bleb
|
IMP
PMID:12686598 Extracellular signal-regulated kinase mediates phosphorylati... |
KEEP AS NON CORE |
Summary: TPM1 localizes to membrane blebs in response to oxidative stress. This relates to cytoskeletal reorganization during stress responses [PMID:12686598].
Reason: Bleb localization is a peripheral cellular component annotation related to stress responses rather than core TPM1 function [PMID:12686598].
Supporting Evidence:
PMID:12686598
presence of H(2)O(2) resulted in a quick and intense membrane blebbing
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GO:0032587
ruffle membrane
|
IDA
PMID:12686598 Extracellular signal-regulated kinase mediates phosphorylati... |
KEEP AS NON CORE |
Summary: ISOFORM-SPECIFIC: TPM1 localizes to ruffle membranes in non-muscle cells. This relates to cytoskeletal actin dynamics at the cell periphery [PMID:12686598].
Reason: Ruffle membrane localization is a cellular component for cytoskeletal TPM1 isoforms in non-muscle cells. This is a peripheral localization related to actin dynamics [PMID:12686598].
Supporting Evidence:
PMID:12686598
tropomyosin-1 was found diffuse in the cells, whereas it quickly colocalized with actin and stress fibers upon stimulation
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GO:0034614
cellular response to reactive oxygen species
|
IEP
PMID:12686598 Extracellular signal-regulated kinase mediates phosphorylati... |
KEEP AS NON CORE |
Summary: TPM1 is phosphorylated in response to oxidative stress via ERK signaling. This leads to cytoskeletal remodeling and affects membrane dynamics [PMID:12686598].
Reason: Response to ROS is a peripheral function related to stress-induced cytoskeletal remodeling. TPM1 phosphorylation downstream of ERK modulates stress fiber formation during oxidative stress [PMID:12686598].
Supporting Evidence:
PMID:12686598
phosphorylation of tropomyosin-1 downstream of ERK by contributing to formation of actin filaments increases cellular contractility and promotes the formation of focal adhesions
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GO:0042060
wound healing
|
ISS
PMID:17721995 Role of high-molecular weight tropomyosins in TGF-beta-media... |
KEEP AS NON CORE |
Summary: ISOFORM-SPECIFIC: TPM1 is involved in wound healing through its role in cytoskeletal remodeling and cell migration during tissue repair [PMID:17721995].
Reason: Wound healing is a peripheral function of cytoskeletal TPM1 isoforms related to cell migration and tissue remodeling. While biologically relevant, this is not a core molecular function [PMID:17721995].
Supporting Evidence:
PMID:17721995
HMW-tropomyosins are important for TGF-beta-mediated control of cell
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GO:0045785
positive regulation of cell adhesion
|
ISS
PMID:17721995 Role of high-molecular weight tropomyosins in TGF-beta-media... |
KEEP AS NON CORE |
Summary: ISOFORM-SPECIFIC: TPM1 promotes cell adhesion by enhancing actin stress fibers and focal adhesions in non-muscle cells [PMID:17721995].
Reason: Regulation of cell adhesion is a peripheral function of cytoskeletal TPM1 isoforms related to stress fiber stabilization [PMID:17721995].
Supporting Evidence:
PMID:17721995
Tropomyosin increased cell adhesion to matrix by enhancing actin fibers and focal adhesions
|
|
GO:0051496
positive regulation of stress fiber assembly
|
ISS
PMID:15897890 Silencing of the Tropomyosin-1 gene by DNA methylation alter... |
ACCEPT |
Summary: ISOFORM-SPECIFIC: TPM1 (HMW tropomyosins) are required for TGF-beta-induced stress fiber assembly in epithelial cells [PMID:15897890].
Reason: Positive regulation of stress fiber assembly is a well-documented function of cytoskeletal TPM1 isoforms. HMW tropomyosins stabilize and promote stress fiber formation [PMID:15897890].
Supporting Evidence:
PMID:15897890
TGF-beta induction of stress fibers in epithelial cells requires high molecular weight tropomyosins encoded by TPM1 and TPM2 genes
|
|
GO:0055010
ventricular cardiac muscle tissue morphogenesis
|
IMP
PMID:11136687 Hypertrophic cardiomyopathy caused by a novel alpha-tropomyo... |
KEEP AS NON CORE |
Summary: ISOFORM-SPECIFIC: Cardiac TPM1 isoforms are essential for ventricular morphogenesis. Mutations cause hypertrophic cardiomyopathy with ventricular hypertrophy [PMID:11136687].
Reason: Ventricular morphogenesis is a developmental process that TPM1 mutations affect. While important, this is a downstream consequence of TPM1's role in cardiac muscle function rather than a core molecular function [PMID:11136687].
Supporting Evidence:
PMID:11136687
The mutation caused a 40% to 50% increase in calcium affinity in regulated thin filament-myosin subfragment-1 (S1) MgATPase assays
|
|
GO:0060048
cardiac muscle contraction
|
IMP
PMID:11136687 Hypertrophic cardiomyopathy caused by a novel alpha-tropomyo... |
ACCEPT |
Summary: ISOFORM-SPECIFIC: This IMP annotation with experimental evidence complements the IBA annotation for cardiac muscle contraction. TPM1 mutations affect Ca2+ sensitivity and muscle contraction [PMID:11136687].
Reason: Cardiac muscle contraction is a core function of cardiac TPM1 isoforms. This experimental annotation provides direct evidence that TPM1 mutations affect cardiac contractile function [PMID:11136687].
Supporting Evidence:
PMID:11136687
The mutation caused a 40% to 50% increase in calcium affinity in regulated thin filament-myosin subfragment-1 (S1) MgATPase assays
|
|
GO:0030017
sarcomere
|
TAS
PMID:16754800 Single-gene mutations and increased left ventricular wall th... |
ACCEPT |
Summary: ISOFORM-SPECIFIC: Sarcomere localization is specific to striated muscle TPM1 isoforms. TPM1 is an integral component of thin filaments in sarcomeres.
Reason: Sarcomere is a core cellular component for muscle TPM1 isoforms. Tropomyosin is an integral part of the thin filament in sarcomeric structures. TAS annotation from literature supports this well-established localization.
Supporting Evidence:
PMID:16754800
Single-gene mutations and increased left ventricular wall thickness in the community: the Framingham Heart Study.
|
|
GO:0005856
cytoskeleton
|
TAS
PMID:16130169 Proteomics of human umbilical vein endothelial cells applied... |
ACCEPT |
Summary: TPM1 is a cytoskeletal protein identified in proteomic studies of endothelial cells. This annotation complements the IEA cytoskeleton annotation.
Reason: Cytoskeleton is a valid cellular component for TPM1. All isoforms are components of the cytoskeleton, whether in sarcomeres or stress fibers. TAS annotation is appropriate.
Supporting Evidence:
PMID:16130169
Proteomics of human umbilical vein endothelial cells applied to etoposide-induced apoptosis.
|
|
GO:0005862
muscle thin filament tropomyosin
|
TAS
PMID:8205619 Alpha-tropomyosin and cardiac troponin T mutations cause fam... |
ACCEPT |
Summary: ISOFORM-SPECIFIC: This TAS annotation complements the IEA annotation for muscle thin filament tropomyosin. TPM1 mutations in this complex cause familial hypertrophic cardiomyopathy [PMID:8205619].
Reason: Muscle thin filament tropomyosin is a core cellular component for muscle TPM1 isoforms. The cited study demonstrates TPM1's role in the thin filament complex and disease consequences of mutations [PMID:8205619].
Supporting Evidence:
PMID:8205619
alpha-tropomyosin and cardiac troponin T as well as beta myosin heavy chain mutations cause the same phenotype, we conclude that FHC is a disease of the sarcomere
|
|
GO:0006937
regulation of muscle contraction
|
TAS
PMID:3336363 Human hTM alpha gene: expression in muscle and nonmuscle tis... |
ACCEPT |
Summary: ISOFORM-SPECIFIC: Regulation of muscle contraction is a core function of muscle TPM1 isoforms. The study describes expression of alpha-tropomyosin in muscle and non-muscle tissues.
Reason: Regulation of muscle contraction is a core biological process for muscle TPM1 isoforms. Tropomyosin regulates actin-myosin interaction in a Ca2+-dependent manner via the troponin complex. TAS annotation is appropriate.
Supporting Evidence:
PMID:3336363
Human hTM alpha gene: expression in muscle and nonmuscle tissue.
|
|
GO:0008016
regulation of heart contraction
|
TAS
PMID:8205619 Alpha-tropomyosin and cardiac troponin T mutations cause fam... |
ACCEPT |
Summary: ISOFORM-SPECIFIC: Cardiac TPM1 isoforms regulate heart contraction. Mutations cause familial hypertrophic cardiomyopathy, demonstrating the essential role of TPM1 in cardiac function [PMID:8205619].
Reason: Regulation of heart contraction is a core function of cardiac TPM1 isoforms. Mutations affecting this function cause cardiomyopathy [PMID:8205619].
Supporting Evidence:
PMID:8205619
We demonstrate that missense mutations (Asp175Asn; Glu180Gly) in the alpha-tropomyosin gene cause familial hypertrophic cardiomyopathy (FHC)
|
|
GO:0008307
structural constituent of muscle
|
TAS
PMID:8205619 Alpha-tropomyosin and cardiac troponin T mutations cause fam... |
ACCEPT |
Summary: ISOFORM-SPECIFIC: Muscle TPM1 isoforms are structural constituents of muscle thin filaments in sarcomeres [PMID:8205619].
Reason: Structural constituent of muscle is a core molecular function for muscle TPM1 isoforms. TPM1 is an integral structural component of thin filaments in sarcomeres [PMID:8205619].
Supporting Evidence:
PMID:8205619
alpha-tropomyosin and cardiac troponin T as well as beta myosin heavy chain mutations cause the same phenotype, we conclude that FHC is a disease of the sarcomere
|
TPM1 has 10 named isoforms with tissue-specific expression patterns.
| Isoform | UniProt ID | Synonym | Tissue | Key Feature |
|---|---|---|---|---|
| Isoform 1 | P09493-1 | TPM1alpha, Skeletal | Skeletal muscle | Adult striated muscle |
| Isoform 2 | P09493-2 | Smooth muscle | Smooth muscle | Vascular, visceral |
| Isoform 3 | P09493-3 | TM3, Fibroblast | Non-muscle cells | Cytoskeletal function |
| Isoform 6 | P09493-6 | TPM1kappa | Cardiac | Cardiac-specific |
Striated muscle isoforms (1, 6):
- Regulate actin-myosin interaction in sarcomeres
- Essential for muscle contraction
- Mutations cause cardiomyopathy
Smooth muscle isoform (2):
- Different N-terminal sequence
- Expressed in blood vessels, uterus, GI tract
- Regulates smooth muscle contraction
Non-muscle isoforms (3, etc.):
- Cytoskeletal organization
- Cell motility
- Different actin binding properties
Cardiomyopathy mutations:
- CMH3: Familial hypertrophic cardiomyopathy
- CMD1Y: Dilated cardiomyopathy
- Mutations affect sarcomere function
UniProt tissue specificity:
"Isoform 1 is expressed in adult and fetal skeletal muscle and cardiac tissues, with higher expression levels in the cardiac tissues. Isoform 10 is expressed in adult and fetal cardiac tissues, but not in skeletal muscle."
id: P09493
gene_symbol: TPM1
product_type: PROTEIN
status: INITIALIZED
taxon:
id: NCBITaxon:9606
label: Homo sapiens
description: 'TPM1 (Tropomyosin 1) is a coiled-coil actin-binding protein with 10
tissue-specific isoforms. ISOFORM BIOLOGY: (1) Isoform 1 (TPM1alpha, P09493-1) is
expressed in SKELETAL MUSCLE; (2) Isoform 2 is SMOOTH MUSCLE-specific; (3) Isoform
3 (TM3) is the FIBROBLAST/cytoskeletal form; (4) Isoform 6 (TPM1kappa) is CARDIAC-specific.
UniProt states "Isoform 1 is expressed in adult and fetal skeletal muscle and cardiac
tissues. Isoform 10 is expressed in adult and fetal cardiac tissues, but not in
skeletal muscle." Muscle isoforms regulate actin-myosin interaction in sarcomeres;
cytoskeletal isoforms organize non-muscle actin. DISEASE: Mutations cause cardiomyopathy
(CMH3, CMD1Y) affecting sarcomere function. Annotations for "muscle contraction"
and "sarcomere" apply primarily to muscle isoforms, while "cytoskeleton organization"
applies more to non-muscle isoforms.'
existing_annotations:
- term:
id: GO:0051015
label: actin filament binding
evidence_type: IBA
original_reference_id: GO_REF:0000033
review:
summary: Core function of all TPM1 isoforms. Tropomyosin binds along the
length of actin filaments in both muscle and non-muscle cells. UniProt
states that TPM1 binds to actin filaments. This function is conserved
across all isoforms - muscle isoforms bind thin filament actin while
cytoskeletal isoforms bind stress fiber actin.
action: ACCEPT
reason: Actin filament binding is the fundamental molecular function of
all tropomyosins. IBA annotation is appropriate as this function is
phylogenetically conserved. Supported by functional studies showing TPM1
binds actin filaments in both muscle and non-muscle contexts
[PMID:12686598].
supported_by:
- reference_id: PMID:12686598
supporting_text: tropomyosin-1 was found diffuse in the cells, whereas
it quickly colocalized with actin and stress fibers upon stimulation
- reference_id: PMID:8205619
supporting_text: alpha-tropomyosin and cardiac troponin T as well as
beta myosin heavy chain mutations cause the same phenotype, we
conclude that FHC is a disease of the sarcomere
- term:
id: GO:0007015
label: actin filament organization
evidence_type: IBA
original_reference_id: GO_REF:0000033
review:
summary: TPM1 plays a role in actin filament organization in both muscle
and non-muscle cells. In muscle, it organizes thin filaments; in
non-muscle cells, it contributes to stress fiber formation and
cytoskeletal organization [PMID:12686598].
action: ACCEPT
reason: Actin filament organization is a core function of tropomyosins
across all isoforms. Muscle isoforms organize thin filaments in
sarcomeres; cytoskeletal isoforms stabilize stress fibers in non-muscle
cells. IBA annotation is appropriate.
supported_by:
- reference_id: PMID:12686598
supporting_text: phosphorylation of tropomyosin-1 downstream of ERK by
contributing to formation of actin filaments increases cellular
contractility and promotes the formation of focal adhesions
- reference_id: PMID:15897890
supporting_text: TGF-beta induction of stress fibers in epithelial
cells requires high molecular weight tropomyosins encoded by TPM1
and TPM2 genes
- term:
id: GO:0005884
label: actin filament
evidence_type: IBA
original_reference_id: GO_REF:0000033
review:
summary: TPM1 localizes to actin filaments in both muscle and non-muscle
cells. This cellular component annotation reflects the physical location
of tropomyosin bound along actin filaments.
action: ACCEPT
reason: Tropomyosin is an integral component of actin filaments. In muscle
cells it forms the thin filament regulatory complex; in non-muscle cells
it associates with stress fibers and other actin structures. IBA
annotation is appropriate.
supported_by:
- reference_id: PMID:12686598
supporting_text: tropomyosin-1 was found diffuse in the cells, whereas
it quickly colocalized with actin and stress fibers upon stimulation
- term:
id: GO:0060048
label: cardiac muscle contraction
evidence_type: IBA
original_reference_id: GO_REF:0000033
review:
summary: 'ISOFORM-SPECIFIC: Cardiac muscle contraction is a function of the
striated muscle isoforms (Isoform 1/TPM1alpha and Isoform 6/TPM1kappa). UniProt
states Isoform 1 is expressed in cardiac tissues and Isoform 6 is cardiac-specific.
Mutations cause cardiomyopathy (CMH3, CMD1Y) [PMID:8205619, PMID:11273725].'
action: ACCEPT
reason: This is a core function for cardiac isoforms. TPM1 plays a central
role in calcium-dependent regulation of cardiac muscle contraction via
the troponin complex. Mutations affecting this function cause
hypertrophic and dilated cardiomyopathy, demonstrating its importance
[PMID:8205619]. IBA annotation is appropriate as this function is
conserved in striated muscle isoforms.
supported_by:
- reference_id: PMID:8205619
supporting_text: We demonstrate that missense mutations (Asp175Asn;
Glu180Gly) in the alpha-tropomyosin gene cause familial hypertrophic
cardiomyopathy (FHC)
- reference_id: PMID:11136687
supporting_text: HCM was linked to the TPM1 gene... The mutation
caused a 40% to 50% increase in calcium affinity in regulated thin
filament-myosin subfragment-1 (S1) MgATPase assays
- term:
id: GO:0003779
label: actin binding
evidence_type: IEA
original_reference_id: GO_REF:0000043
review:
summary: Actin binding is the fundamental molecular function of all
tropomyosins. This IEA annotation based on UniProt keyword mapping is
correct but less specific than GO:0051015 (actin filament binding) which
is already annotated via IBA.
action: ACCEPT
reason: While this is a broader parent term of actin filament binding, it
is still correct. IEA annotations at a broader level are acceptable
alongside more specific experimental annotations. No action needed as
the more specific IBA annotation (GO:0051015) captures the precise
function.
supported_by:
- reference_id: PMID:12686598
supporting_text: tropomyosin-1 was found diffuse in the cells, whereas
it quickly colocalized with actin and stress fibers upon stimulation
- term:
id: GO:0005856
label: cytoskeleton
evidence_type: IEA
original_reference_id: GO_REF:0000044
review:
summary: TPM1 is a cytoskeletal protein. UniProt subcellular location
indicates "Cytoplasm, cytoskeleton" and notes it "Associates with
F-actin stress fibers." This is a broad cellular component annotation
appropriate for all isoforms.
action: ACCEPT
reason: This is a valid broad localization term. All TPM1 isoforms are
components of the cytoskeleton, whether in sarcomeres (muscle isoforms)
or stress fibers (non-muscle isoforms). IEA based on UniProt subcellular
location is appropriate.
supported_by:
- reference_id: PMID:12686598
supporting_text: tropomyosin-1 was found diffuse in the cells, whereas
it quickly colocalized with actin and stress fibers upon stimulation
- term:
id: GO:0005862
label: muscle thin filament tropomyosin
evidence_type: IEA
original_reference_id: GO_REF:0000117
review:
summary: 'ISOFORM-SPECIFIC: This cellular component term is specifically for
muscle isoforms (Isoform 1/skeletal, Isoform 2/smooth, Isoform 6/cardiac).
The muscle thin filament tropomyosin complex contains tropomyosin bound to
actin filaments in sarcomeres. Non-muscle isoforms (e.g., Isoform 3/fibroblast)
do not form this specific complex.'
action: ACCEPT
reason: This is a core localization for muscle isoforms of TPM1. The
annotation is correct for the muscle-expressed isoforms that are
integral to the thin filament regulatory complex in sarcomeres
[PMID:8205619].
supported_by:
- reference_id: PMID:8205619
supporting_text: FHC is a disease of the sarcomere
- reference_id: PMID:11136687
supporting_text: regulated thin filament-myosin subfragment-1 (S1)
MgATPase assays
- term:
id: GO:0005515
label: protein binding
evidence_type: IPI
original_reference_id: PMID:16189514
review:
summary: High-throughput Y2H interactome study. The term "protein binding"
is uninformative and does not indicate specific binding partners or
functional context. TPM1 binds actin, troponins, and other
muscle/cytoskeletal proteins, but this generic term does not capture
those specific interactions.
action: MARK_AS_OVER_ANNOTATED
reason: '"Protein binding" (GO:0005515) is an uninformative annotation that
does not convey the specific molecular interactions of TPM1 (e.g., actin binding,
troponin complex binding). High-throughput interactome studies often generate
these generic annotations. More specific MF terms are preferred [PMID:16189514].'
supported_by:
- reference_id: PMID:16189514
supporting_text: Using a stringent, high-throughput yeast two-hybrid
system, we tested pairwise interactions among the products of
approximately 8,100 currently available Gateway-cloned open reading
frames and detected approximately 2,800 interactions
- term:
id: GO:0005515
label: protein binding
evidence_type: IPI
original_reference_id: PMID:21516116
review:
summary: High-throughput Stitch-seq Y2H interactome study. The generic
term "protein binding" is uninformative for this well-characterized
actin-binding protein.
action: MARK_AS_OVER_ANNOTATED
reason: '"Protein binding" (GO:0005515) from high-throughput interactome studies
is too generic. TPM1 has specific, well-characterized binding partners (actin,
troponins, LMOD2, TMOD1) that are more informative [PMID:21516116].'
supported_by:
- reference_id: PMID:21516116
supporting_text: We describe a massively parallel interactome-mapping
pipeline, Stitch-seq, that combines PCR stitching with
next-generation sequencing and used it to generate a new human
interactome dataset
- term:
id: GO:0005515
label: protein binding
evidence_type: IPI
original_reference_id: PMID:25416956
review:
summary: Large-scale proteome-scale human interactome map study. Generic
"protein binding" term is uninformative for TPM1 which has
well-characterized specific interactions.
action: MARK_AS_OVER_ANNOTATED
reason: '"Protein binding" (GO:0005515) from systematic interactome mapping
is too generic. TPM1 has specific, functionally important binding partners
that should be annotated instead [PMID:25416956].'
supported_by:
- reference_id: PMID:25416956
supporting_text: Here, we describe a systematic map of ?14,000
high-quality human binary protein-protein interactions
- term:
id: GO:0005515
label: protein binding
evidence_type: IPI
original_reference_id: PMID:26871637
review:
summary: Study on alternative splicing and protein interaction
capabilities. Notably relevant for TPM1 which has 10 isoforms with
different interaction profiles. However "protein binding" remains
uninformative.
action: MARK_AS_OVER_ANNOTATED
reason: While this study is highly relevant to TPM1 isoform biology,
showing that alternative isoforms exhibit different interaction
profiles, the generic "protein binding" term does not capture the
specific binding partners or isoform-specific interactions
[PMID:26871637].
supported_by:
- reference_id: PMID:26871637
supporting_text: The majority of isoform pairs share less than 50% of
their interactions. In the global context of interactome network
maps, alternative isoforms tend to behave like distinct proteins
rather than minor variants of each other
- term:
id: GO:0005515
label: protein binding
evidence_type: IPI
original_reference_id: PMID:30021884
review:
summary: Crosslinking mass spectrometry study of histone interactions in
nuclei. TPM1 is a cytoplasmic/cytoskeletal protein; its detection here
may be incidental. Generic "protein binding" term is uninformative.
action: MARK_AS_OVER_ANNOTATED
reason: '"Protein binding" from crosslinking MS study of nuclear proteins is
not informative for TPM1, which is primarily a cytoskeletal protein. The generic
term provides no functional insight [PMID:30021884].'
supported_by:
- reference_id: PMID:30021884
supporting_text: Here we use crosslinking mass spectrometry (XL-MS) to
chart the protein-protein interactions in intact human nuclei
- term:
id: GO:0005515
label: protein binding
evidence_type: IPI
original_reference_id: PMID:33961781
review:
summary: BioPlex 3.0 dual proteome-scale network study in 293T and HCT116
cells. While this reveals cell-specific interactome remodeling relevant
to TPM1 isoforms, the generic "protein binding" term is uninformative.
action: MARK_AS_OVER_ANNOTATED
reason: '"Protein binding" from large-scale AP-MS interactome study does not
provide specific information about TPM1''s functional binding partners. More
specific terms for actin binding, troponin binding etc. are preferred [PMID:33961781].'
supported_by:
- reference_id: PMID:33961781
supporting_text: Thousands of interactions assemble proteins into
modules that impart spatial and functional organization to the
cellular proteome
- term:
id: GO:0005515
label: protein binding
evidence_type: IPI
original_reference_id: PMID:40205054
review:
summary: Multimodal cell maps study integrating multiple data types for
structural and functional genomics. Generic "protein binding" term is
uninformative.
action: MARK_AS_OVER_ANNOTATED
reason: '"Protein binding" from multimodal cell mapping study does not convey
specific information about TPM1''s well-characterized binding partners [PMID:40205054].'
supported_by:
- reference_id: PMID:40205054
supporting_text: Multimodal cell maps as a foundation for structural
and functional genomics
- term:
id: GO:0005515
label: protein binding
evidence_type: IPI
original_reference_id: PMID:25910212
isoform: P09493-10
review:
summary: ISOFORM-SPECIFIC ANNOTATION (P09493-10). Study on macromolecular
interaction perturbations in genetic disorders. While highly relevant to
understanding how TPM1 mutations affect interactions, "protein binding"
is uninformative.
action: MARK_AS_OVER_ANNOTATED
reason: '"Protein binding" from edgetic mutation studies is too generic. This
study shows disease mutations can perturb specific interactions, but the annotation
lacks specificity about which interactions [PMID:25910212].'
supported_by:
- reference_id: PMID:25910212
supporting_text: While common variants from healthy individuals rarely
affect interactions, two-thirds of disease-associated alleles
perturb protein-protein interactions, with half corresponding to
"edgetic" alleles affecting only a subset of interactions while
leaving most other interactions unperturbed
- term:
id: GO:0005515
label: protein binding
evidence_type: IPI
original_reference_id: PMID:32296183
isoform: P09493-10
review:
summary: ISOFORM-SPECIFIC ANNOTATION (P09493-10). HuRI reference human
binary protein interactome map. While highly valuable for mapping
interactions, the generic "protein binding" term is uninformative for
TPM1.
action: MARK_AS_OVER_ANNOTATED
reason: '"Protein binding" from the comprehensive HuRI interactome map does
not convey specific binding partners. TPM1 has well-characterized interactions
with actin, troponins, and other thin filament proteins that are more informative
[PMID:32296183].'
supported_by:
- reference_id: PMID:32296183
supporting_text: Here we present a human 'all-by-all' reference
interactome map of human binary protein interactions, or 'HuRI'
- term:
id: GO:0042802
label: identical protein binding
evidence_type: ISS
original_reference_id: GO_REF:0000024
review:
summary: Tropomyosins form coiled-coil dimers (homo- or heterodimers) as
their functional unit. UniProt indicates TPM1 forms dimers with itself
or other tropomyosin isoforms. This ISS annotation from sequence
similarity is consistent with the coiled-coil structure of tropomyosins.
action: ACCEPT
reason: TPM1 forms parallel coiled-coil dimers that bind along actin
filaments. This is a fundamental structural property of all
tropomyosins. Self-association (homodimerization) is documented in
UniProt. ISS annotation based on sequence similarity to characterized
orthologs is appropriate.
- term:
id: GO:0042803
label: protein homodimerization activity
evidence_type: ISS
original_reference_id: GO_REF:0000024
review:
summary: Tropomyosins function as coiled-coil dimers. TPM1 homodimerizes
to form the functional unit that binds along actin filaments. This is a
core structural property of tropomyosins.
action: ACCEPT
reason: Homodimerization is fundamental to tropomyosin function. Two TPM1
chains form a parallel coiled-coil dimer that spans seven actin
subunits. ISS annotation based on sequence similarity is appropriate for
this conserved structural property.
- term:
id: GO:0046982
label: protein heterodimerization activity
evidence_type: ISS
original_reference_id: GO_REF:0000024
review:
summary: TPM1 can form heterodimers with other tropomyosin isoforms (e.g.,
TPM2, TPM3). UniProt indicates it interacts with self or TPM2.
Heterodimer formation provides functional diversity in different tissue
contexts.
action: ACCEPT
reason: Heterodimerization with other tropomyosin isoforms is a documented
property that provides functional diversity. TPM1 can form dimers with
TPM2 and potentially other isoforms. ISS annotation based on sequence
similarity is appropriate.
- term:
id: GO:0051015
label: actin filament binding
evidence_type: ISS
original_reference_id: GO_REF:0000024
review:
summary: Duplicate of the IBA annotation for actin filament binding. This
ISS annotation provides additional evidence for this core function from
sequence similarity.
action: ACCEPT
reason: Actin filament binding is the fundamental molecular function of
TPM1 across all isoforms. This ISS annotation supplements the IBA
annotation and is consistent with the conserved function of
tropomyosins.
- term:
id: GO:0008360
label: regulation of cell shape
evidence_type: IMP
original_reference_id: PMID:21817107
review:
summary: 'ISOFORM-SPECIFIC: This annotation relates to the cytoskeletal (non-muscle)
function of TPM1 isoforms. The study shows TPM1 affects vascular smooth muscle
cell morphology via cytoskeletal remodeling [PMID:21817107].'
action: KEEP_AS_NON_CORE
reason: Regulation of cell shape is a function of cytoskeletal TPM1
isoforms in non-muscle cells. While important, it is not the core
function of the striated muscle isoforms. This is a valid annotation for
cytoskeletal isoforms [PMID:21817107].
supported_by:
- reference_id: PMID:21817107
supporting_text: cell proliferation and migration were significantly
decreased by
- term:
id: GO:1904706
label: negative regulation of vascular associated smooth muscle cell
proliferation
evidence_type: IMP
original_reference_id: PMID:21817107
review:
summary: 'ISOFORM-SPECIFIC: TPM1 overexpression inhibits vascular smooth muscle
cell (VSMC) proliferation. This relates to the cytoskeletal function of TPM1
in regulating cell behavior [PMID:21817107].'
action: KEEP_AS_NON_CORE
reason: This is a valid functional annotation for cytoskeletal TPM1
isoforms in smooth muscle cells. While biologically relevant, it
represents a peripheral function rather than the core sarcomeric
function of TPM1 [PMID:21817107].
supported_by:
- reference_id: PMID:21817107
supporting_text: cell proliferation and migration were significantly
decreased by
- term:
id: GO:1904753
label: negative regulation of vascular associated smooth muscle cell
migration
evidence_type: IMP
original_reference_id: PMID:21817107
review:
summary: 'ISOFORM-SPECIFIC: TPM1 overexpression inhibits vascular smooth muscle
cell (VSMC) migration. This relates to the cytoskeletal function of TPM1 in
regulating cell motility [PMID:21817107].'
action: KEEP_AS_NON_CORE
reason: This is a valid functional annotation for cytoskeletal TPM1
isoforms in smooth muscle cells. While biologically relevant, it
represents a peripheral function rather than the core sarcomeric
function of TPM1 [PMID:21817107].
supported_by:
- reference_id: PMID:21817107
supporting_text: cell proliferation and migration were significantly
decreased by
- term:
id: GO:0005829
label: cytosol
evidence_type: TAS
original_reference_id: Reactome:R-HSA-390593
review:
summary: Reactome pathway annotation for muscle contraction. TPM1 is a
cytosolic/ cytoskeletal protein that associates with actin filaments.
Cytosol localization is valid for soluble tropomyosin before assembly.
action: ACCEPT
reason: Cytosol is an appropriate cellular component for TPM1. Prior to
incorporation into actin filaments, tropomyosin exists in the cytosol.
Reactome pathway annotations for muscle contraction support this
localization.
- term:
id: GO:0005829
label: cytosol
evidence_type: TAS
original_reference_id: Reactome:R-HSA-390595
review:
summary: Duplicate Reactome pathway annotation for cytosol localization in
muscle contraction pathway.
action: ACCEPT
reason: Valid cellular component annotation from Reactome muscle
contraction pathway. Cytosol localization is appropriate for soluble
tropomyosin.
- term:
id: GO:0005829
label: cytosol
evidence_type: TAS
original_reference_id: Reactome:R-HSA-390597
review:
summary: Duplicate Reactome pathway annotation for cytosol localization.
action: ACCEPT
reason: Valid cellular component annotation from Reactome pathway. Cytosol
localization is appropriate for soluble tropomyosin.
- term:
id: GO:0005829
label: cytosol
evidence_type: TAS
original_reference_id: Reactome:R-HSA-390598
review:
summary: Duplicate Reactome pathway annotation for cytosol localization.
action: ACCEPT
reason: Valid cellular component annotation from Reactome pathway. Cytosol
localization is appropriate for soluble tropomyosin.
- term:
id: GO:0005829
label: cytosol
evidence_type: TAS
original_reference_id: Reactome:R-HSA-445699
review:
summary: Duplicate Reactome pathway annotation for cytosol localization.
action: ACCEPT
reason: Valid cellular component annotation from Reactome pathway. Cytosol
localization is appropriate for soluble tropomyosin.
- term:
id: GO:0005829
label: cytosol
evidence_type: TAS
original_reference_id: Reactome:R-HSA-445700
review:
summary: Duplicate Reactome pathway annotation for cytosol localization.
action: ACCEPT
reason: Valid cellular component annotation from Reactome pathway. Cytosol
localization is appropriate for soluble tropomyosin.
- term:
id: GO:0005829
label: cytosol
evidence_type: TAS
original_reference_id: Reactome:R-HSA-445704
review:
summary: Duplicate Reactome pathway annotation for cytosol localization.
action: ACCEPT
reason: Valid cellular component annotation from Reactome pathway. Cytosol
localization is appropriate for soluble tropomyosin.
- term:
id: GO:0005829
label: cytosol
evidence_type: TAS
original_reference_id: Reactome:R-HSA-445705
review:
summary: Duplicate Reactome pathway annotation for cytosol localization.
action: ACCEPT
reason: Valid cellular component annotation from Reactome pathway. Cytosol
localization is appropriate for soluble tropomyosin.
- term:
id: GO:0008092
label: cytoskeletal protein binding
evidence_type: IPI
original_reference_id: PMID:17987659
review:
summary: TPM1 binds cytoskeletal proteins including nebulette. The study
identified tropomyosin-1 as a binding partner of nebulette in a yeast
two-hybrid screen [PMID:17987659].
action: ACCEPT
reason: Cytoskeletal protein binding accurately describes TPM1's
interactions with actin filaments and associated regulatory proteins.
This is a valid molecular function annotation that is more specific than
"protein binding".
supported_by:
- reference_id: PMID:17987659
supporting_text: Nebulette interacts with filamin C.
- term:
id: GO:0045214
label: sarcomere organization
evidence_type: IMP
original_reference_id: PMID:11273725
review:
summary: 'ISOFORM-SPECIFIC: Sarcomere organization is a function of muscle isoforms.
TPM1 mutations cause disorganized sarcomere structure in cardiomyopathy [PMID:11273725].'
action: ACCEPT
reason: Sarcomere organization is a core function of striated muscle TPM1
isoforms. Mutations affecting this function cause hypertrophic and
dilated cardiomyopathy. This is a well-supported experimental annotation
[PMID:11273725].
supported_by:
- reference_id: PMID:11273725
supporting_text: Proteins in cardiac myocytes assemble into
contractile units known as sarcomeres
- term:
id: GO:0001725
label: stress fiber
evidence_type: IDA
original_reference_id: PMID:12686598
review:
summary: 'ISOFORM-SPECIFIC: TPM1 localizes to stress fibers in non-muscle cells.
The study shows TPM1 colocalizes with actin stress fibers upon stimulation
[PMID:12686598].'
action: ACCEPT
reason: Stress fiber localization is a valid cellular component annotation
for cytoskeletal TPM1 isoforms (e.g., Isoform 3/TM3). IDA evidence from
direct observation of colocalization with stress fibers [PMID:12686598].
supported_by:
- reference_id: PMID:12686598
supporting_text: tropomyosin-1 was found diffuse in the cells, whereas
it quickly colocalized with actin and stress fibers upon stimulation
- term:
id: GO:0003065
label: positive regulation of heart rate by epinephrine
evidence_type: ISS
original_reference_id: PMID:17556658
review:
summary: 'ISOFORM-SPECIFIC: This relates to cardiac isoforms (TPM1alpha, TPM1kappa)
and their role in beta-adrenergic signaling in the heart. Tropomyosin phosphorylation
modulates cardiac contractility.'
action: KEEP_AS_NON_CORE
reason: While TPM1 is involved in cardiac muscle contraction, the specific
role in epinephrine-mediated heart rate regulation is indirect via
modulation of thin filament Ca2+ sensitivity. This is a secondary
function rather than a core molecular function.
supported_by:
- reference_id: PMID:17556658
supporting_text: 2007 Jun 7. Dilated cardiomyopathy mutant tropomyosin
mice develop cardiac dysfunction with significantly decreased
fractional shortening and myofilament calcium sensitivity.
- term:
id: GO:0003779
label: actin binding
evidence_type: TAS
original_reference_id: PMID:12686598
review:
summary: Core function of TPM1. Actin binding is fundamental to all TPM1
isoforms. This TAS annotation based on literature review is consistent
with the well-established role of tropomyosin [PMID:12686598].
action: ACCEPT
reason: Actin binding is the fundamental molecular function of
tropomyosin. This annotation supplements the more specific "actin
filament binding" term already annotated via IBA [PMID:12686598].
supported_by:
- reference_id: PMID:12686598
supporting_text: tropomyosin-1 was found diffuse in the cells, whereas
it quickly colocalized with actin and stress fibers upon stimulation
- term:
id: GO:0005200
label: structural constituent of cytoskeleton
evidence_type: TAS
original_reference_id: PMID:12686598
review:
summary: TPM1 is a structural component of the actin cytoskeleton in both
muscle and non-muscle cells. In muscle cells it forms thin filaments; in
non-muscle cells it stabilizes stress fibers [PMID:12686598].
action: ACCEPT
reason: Structural constituent of cytoskeleton is an accurate molecular
function for TPM1. Tropomyosin provides structural stability to actin
filaments and is integral to cytoskeletal architecture [PMID:12686598].
supported_by:
- reference_id: PMID:12686598
supporting_text: phosphorylation of tropomyosin-1 downstream of ERK by
contributing to formation of actin filaments increases cellular
contractility and promotes the formation of focal adhesions
- term:
id: GO:0007010
label: cytoskeleton organization
evidence_type: TAS
original_reference_id: PMID:12686598
review:
summary: TPM1 contributes to cytoskeleton organization in both muscle and
non-muscle cells. This is closely related to actin filament organization
[PMID:12686598].
action: ACCEPT
reason: Cytoskeleton organization is a core function of TPM1 across all
isoforms. In muscle, it organizes sarcomere thin filaments; in
non-muscle cells, it contributes to stress fiber organization
[PMID:12686598].
supported_by:
- reference_id: PMID:12686598
supporting_text: phosphorylation of tropomyosin-1 downstream of ERK by
contributing to formation of actin filaments increases cellular
contractility and promotes the formation of focal adhesions
- term:
id: GO:0030049
label: muscle filament sliding
evidence_type: ISS
original_reference_id: PMID:11136687
review:
summary: 'ISOFORM-SPECIFIC: Muscle filament sliding is a function of striated
muscle isoforms. TPM1 regulates the interaction between thin and thick filaments
during muscle contraction [PMID:11136687].'
action: ACCEPT
reason: Muscle filament sliding is a core function of muscle TPM1
isoforms. Tropomyosin regulates the actin-myosin interaction that drives
filament sliding during contraction. Mutations affecting this cause
cardiomyopathy [PMID:11136687].
supported_by:
- reference_id: PMID:11136687
supporting_text: The mutation caused a 40% to 50% increase in calcium
affinity in regulated thin filament-myosin subfragment-1 (S1)
MgATPase assays
- term:
id: GO:0030336
label: negative regulation of cell migration
evidence_type: ISS
original_reference_id: PMID:15897890
review:
summary: 'ISOFORM-SPECIFIC: Cytoskeletal TPM1 isoforms regulate cell migration.
High molecular weight tropomyosins stabilize stress fibers and inhibit cell
motility [PMID:15897890].'
action: KEEP_AS_NON_CORE
reason: Regulation of cell migration is a function of cytoskeletal TPM1
isoforms in non-muscle cells. While valid, this is a peripheral function
related to the core actin-binding activity [PMID:15897890].
supported_by:
- reference_id: PMID:15897890
supporting_text: TGF-beta induction of stress fibers in epithelial
cells requires high molecular weight tropomyosins encoded by TPM1
and TPM2 genes
- term:
id: GO:0031529
label: ruffle organization
evidence_type: ISS
original_reference_id: PMID:15897890
review:
summary: 'ISOFORM-SPECIFIC: TPM1 affects membrane ruffle organization in non-muscle
cells. This relates to cytoskeletal actin dynamics [PMID:15897890].'
action: KEEP_AS_NON_CORE
reason: Ruffle organization is a function of cytoskeletal TPM1 isoforms in
non-muscle cells. This is a peripheral function related to the core
actin-organizing activity [PMID:15897890].
supported_by:
- reference_id: PMID:15897890
supporting_text: TGF-beta induction of stress fibers in epithelial
cells requires high molecular weight tropomyosins encoded by TPM1
and TPM2 genes
- term:
id: GO:0032059
label: bleb
evidence_type: IMP
original_reference_id: PMID:12686598
review:
summary: TPM1 localizes to membrane blebs in response to oxidative stress.
This relates to cytoskeletal reorganization during stress responses
[PMID:12686598].
action: KEEP_AS_NON_CORE
reason: Bleb localization is a peripheral cellular component annotation
related to stress responses rather than core TPM1 function
[PMID:12686598].
supported_by:
- reference_id: PMID:12686598
supporting_text: presence of H(2)O(2) resulted in a quick and intense
membrane blebbing
- term:
id: GO:0032587
label: ruffle membrane
evidence_type: IDA
original_reference_id: PMID:12686598
review:
summary: 'ISOFORM-SPECIFIC: TPM1 localizes to ruffle membranes in non-muscle
cells. This relates to cytoskeletal actin dynamics at the cell periphery [PMID:12686598].'
action: KEEP_AS_NON_CORE
reason: Ruffle membrane localization is a cellular component for
cytoskeletal TPM1 isoforms in non-muscle cells. This is a peripheral
localization related to actin dynamics [PMID:12686598].
supported_by:
- reference_id: PMID:12686598
supporting_text: tropomyosin-1 was found diffuse in the cells, whereas
it quickly colocalized with actin and stress fibers upon stimulation
- term:
id: GO:0034614
label: cellular response to reactive oxygen species
evidence_type: IEP
original_reference_id: PMID:12686598
review:
summary: TPM1 is phosphorylated in response to oxidative stress via ERK
signaling. This leads to cytoskeletal remodeling and affects membrane
dynamics [PMID:12686598].
action: KEEP_AS_NON_CORE
reason: Response to ROS is a peripheral function related to stress-induced
cytoskeletal remodeling. TPM1 phosphorylation downstream of ERK
modulates stress fiber formation during oxidative stress
[PMID:12686598].
supported_by:
- reference_id: PMID:12686598
supporting_text: phosphorylation of tropomyosin-1 downstream of ERK by
contributing to formation of actin filaments increases cellular
contractility and promotes the formation of focal adhesions
- term:
id: GO:0042060
label: wound healing
evidence_type: ISS
original_reference_id: PMID:17721995
review:
summary: 'ISOFORM-SPECIFIC: TPM1 is involved in wound healing through its role
in cytoskeletal remodeling and cell migration during tissue repair [PMID:17721995].'
action: KEEP_AS_NON_CORE
reason: Wound healing is a peripheral function of cytoskeletal TPM1
isoforms related to cell migration and tissue remodeling. While
biologically relevant, this is not a core molecular function
[PMID:17721995].
supported_by:
- reference_id: PMID:17721995
supporting_text: HMW-tropomyosins are important for TGF-beta-mediated
control of cell
- term:
id: GO:0045785
label: positive regulation of cell adhesion
evidence_type: ISS
original_reference_id: PMID:17721995
review:
summary: 'ISOFORM-SPECIFIC: TPM1 promotes cell adhesion by enhancing actin stress
fibers and focal adhesions in non-muscle cells [PMID:17721995].'
action: KEEP_AS_NON_CORE
reason: Regulation of cell adhesion is a peripheral function of
cytoskeletal TPM1 isoforms related to stress fiber stabilization
[PMID:17721995].
supported_by:
- reference_id: PMID:17721995
supporting_text: Tropomyosin increased cell adhesion to matrix by
enhancing actin fibers and focal adhesions
- term:
id: GO:0051496
label: positive regulation of stress fiber assembly
evidence_type: ISS
original_reference_id: PMID:15897890
review:
summary: 'ISOFORM-SPECIFIC: TPM1 (HMW tropomyosins) are required for TGF-beta-induced
stress fiber assembly in epithelial cells [PMID:15897890].'
action: ACCEPT
reason: Positive regulation of stress fiber assembly is a well-documented
function of cytoskeletal TPM1 isoforms. HMW tropomyosins stabilize and
promote stress fiber formation [PMID:15897890].
supported_by:
- reference_id: PMID:15897890
supporting_text: TGF-beta induction of stress fibers in epithelial
cells requires high molecular weight tropomyosins encoded by TPM1
and TPM2 genes
- term:
id: GO:0055010
label: ventricular cardiac muscle tissue morphogenesis
evidence_type: IMP
original_reference_id: PMID:11136687
review:
summary: 'ISOFORM-SPECIFIC: Cardiac TPM1 isoforms are essential for ventricular
morphogenesis. Mutations cause hypertrophic cardiomyopathy with ventricular
hypertrophy [PMID:11136687].'
action: KEEP_AS_NON_CORE
reason: Ventricular morphogenesis is a developmental process that TPM1
mutations affect. While important, this is a downstream consequence of
TPM1's role in cardiac muscle function rather than a core molecular
function [PMID:11136687].
supported_by:
- reference_id: PMID:11136687
supporting_text: The mutation caused a 40% to 50% increase in calcium
affinity in regulated thin filament-myosin subfragment-1 (S1)
MgATPase assays
- term:
id: GO:0060048
label: cardiac muscle contraction
evidence_type: IMP
original_reference_id: PMID:11136687
review:
summary: 'ISOFORM-SPECIFIC: This IMP annotation with experimental evidence complements
the IBA annotation for cardiac muscle contraction. TPM1 mutations affect Ca2+
sensitivity and muscle contraction [PMID:11136687].'
action: ACCEPT
reason: Cardiac muscle contraction is a core function of cardiac TPM1
isoforms. This experimental annotation provides direct evidence that
TPM1 mutations affect cardiac contractile function [PMID:11136687].
supported_by:
- reference_id: PMID:11136687
supporting_text: The mutation caused a 40% to 50% increase in calcium
affinity in regulated thin filament-myosin subfragment-1 (S1)
MgATPase assays
- term:
id: GO:0030017
label: sarcomere
evidence_type: TAS
original_reference_id: PMID:16754800
review:
summary: 'ISOFORM-SPECIFIC: Sarcomere localization is specific to striated muscle
TPM1 isoforms. TPM1 is an integral component of thin filaments in sarcomeres.'
action: ACCEPT
reason: Sarcomere is a core cellular component for muscle TPM1 isoforms.
Tropomyosin is an integral part of the thin filament in sarcomeric
structures. TAS annotation from literature supports this
well-established localization.
supported_by:
- reference_id: PMID:16754800
supporting_text: 'Single-gene mutations and increased left ventricular wall
thickness in the community: the Framingham Heart Study.'
- term:
id: GO:0005856
label: cytoskeleton
evidence_type: TAS
original_reference_id: PMID:16130169
review:
summary: TPM1 is a cytoskeletal protein identified in proteomic studies of
endothelial cells. This annotation complements the IEA cytoskeleton
annotation.
action: ACCEPT
reason: Cytoskeleton is a valid cellular component for TPM1. All isoforms
are components of the cytoskeleton, whether in sarcomeres or stress
fibers. TAS annotation is appropriate.
supported_by:
- reference_id: PMID:16130169
supporting_text: Proteomics of human umbilical vein endothelial cells
applied to etoposide-induced apoptosis.
- term:
id: GO:0005862
label: muscle thin filament tropomyosin
evidence_type: TAS
original_reference_id: PMID:8205619
review:
summary: 'ISOFORM-SPECIFIC: This TAS annotation complements the IEA annotation
for muscle thin filament tropomyosin. TPM1 mutations in this complex cause
familial hypertrophic cardiomyopathy [PMID:8205619].'
action: ACCEPT
reason: Muscle thin filament tropomyosin is a core cellular component for
muscle TPM1 isoforms. The cited study demonstrates TPM1's role in the
thin filament complex and disease consequences of mutations
[PMID:8205619].
supported_by:
- reference_id: PMID:8205619
supporting_text: alpha-tropomyosin and cardiac troponin T as well as
beta myosin heavy chain mutations cause the same phenotype, we
conclude that FHC is a disease of the sarcomere
- term:
id: GO:0006937
label: regulation of muscle contraction
evidence_type: TAS
original_reference_id: PMID:3336363
review:
summary: 'ISOFORM-SPECIFIC: Regulation of muscle contraction is a core function
of muscle TPM1 isoforms. The study describes expression of alpha-tropomyosin
in muscle and non-muscle tissues.'
action: ACCEPT
reason: Regulation of muscle contraction is a core biological process for
muscle TPM1 isoforms. Tropomyosin regulates actin-myosin interaction in
a Ca2+-dependent manner via the troponin complex. TAS annotation is
appropriate.
supported_by:
- reference_id: PMID:3336363
supporting_text: 'Human hTM alpha gene: expression in muscle and nonmuscle
tissue.'
- term:
id: GO:0008016
label: regulation of heart contraction
evidence_type: TAS
original_reference_id: PMID:8205619
review:
summary: 'ISOFORM-SPECIFIC: Cardiac TPM1 isoforms regulate heart contraction.
Mutations cause familial hypertrophic cardiomyopathy, demonstrating the essential
role of TPM1 in cardiac function [PMID:8205619].'
action: ACCEPT
reason: Regulation of heart contraction is a core function of cardiac TPM1
isoforms. Mutations affecting this function cause cardiomyopathy
[PMID:8205619].
supported_by:
- reference_id: PMID:8205619
supporting_text: We demonstrate that missense mutations (Asp175Asn;
Glu180Gly) in the alpha-tropomyosin gene cause familial hypertrophic
cardiomyopathy (FHC)
- term:
id: GO:0008307
label: structural constituent of muscle
evidence_type: TAS
original_reference_id: PMID:8205619
review:
summary: 'ISOFORM-SPECIFIC: Muscle TPM1 isoforms are structural constituents
of muscle thin filaments in sarcomeres [PMID:8205619].'
action: ACCEPT
reason: Structural constituent of muscle is a core molecular function for
muscle TPM1 isoforms. TPM1 is an integral structural component of thin
filaments in sarcomeres [PMID:8205619].
supported_by:
- reference_id: PMID:8205619
supporting_text: alpha-tropomyosin and cardiac troponin T as well as
beta myosin heavy chain mutations cause the same phenotype, we
conclude that FHC is a disease of the sarcomere
core_functions:
- molecular_function:
id: GO:0051015
label: actin filament binding
description: Actin filament binding is the fundamental molecular function of
all TPM1 isoforms. Tropomyosin dimers bind along the length of actin
filaments in both muscle (thin filaments) and non-muscle (stress fibers)
cells, stabilizing actin filaments and regulating their interactions with
other proteins.
directly_involved_in:
- id: GO:0007015
label: actin filament organization
locations:
- id: GO:0005884
label: actin filament
- molecular_function:
id: GO:0051015
label: actin filament binding
description: 'ISOFORM-SPECIFIC (Cardiac isoforms): Cardiac muscle contraction
is a core function of striated muscle isoforms (TPM1alpha, TPM1kappa). TPM1
regulates calcium-dependent actin-myosin interaction via the troponin complex.
Mutations cause cardiomyopathy (CMH3, CMD1Y).'
directly_involved_in:
- id: GO:0060048
label: cardiac muscle contraction
- id: GO:0006937
label: regulation of muscle contraction
locations:
- id: GO:0030017
label: sarcomere
in_complex:
id: GO:0005862
label: muscle thin filament tropomyosin
- molecular_function:
id: GO:0051015
label: actin filament binding
description: 'ISOFORM-SPECIFIC (Cytoskeletal isoforms): Non-muscle TPM1 isoforms
(e.g., TM3) bind actin filaments in stress fibers and contribute to cytoskeletal
organization, cell shape regulation, and cell motility.'
directly_involved_in:
- id: GO:0007015
label: actin filament organization
- id: GO:0051496
label: positive regulation of stress fiber assembly
locations:
- id: GO:0001725
label: stress fiber
references:
- id: GO_REF:0000024
title: Manual transfer of experimentally-verified manual GO annotation data
to orthologs by curator judgment of sequence similarity
findings: []
- id: GO_REF:0000033
title: Annotation inferences using phylogenetic trees
findings: []
- id: GO_REF:0000043
title: Gene Ontology annotation based on UniProtKB/Swiss-Prot keyword
mapping
findings: []
- id: GO_REF:0000044
title: Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular
Location vocabulary mapping, accompanied by conservative changes to GO
terms applied by UniProt
findings: []
- id: GO_REF:0000117
title: Electronic Gene Ontology annotations created by ARBA machine learning
models
findings: []
- id: PMID:11136687
title: Hypertrophic cardiomyopathy caused by a novel alpha-tropomyosin
mutation (V95A) is associated with mild cardiac phenotype, abnormal
calcium binding to troponin, abnormal myosin cycling, and poor prognosis.
findings: []
- id: PMID:11273725
title: Mutations that alter the surface charge of alpha-tropomyosin are
associated with dilated cardiomyopathy.
findings: []
- id: PMID:12686598
title: 'Extracellular signal-regulated kinase mediates phosphorylation of tropomyosin-1
to promote cytoskeleton remodeling in response to oxidative stress: impact on
membrane blebbing.'
findings: []
- id: PMID:15897890
title: Silencing of the Tropomyosin-1 gene by DNA methylation alters tumor
suppressor function of TGF-beta.
findings: []
- id: PMID:16130169
title: Proteomics of human umbilical vein endothelial cells applied to
etoposide-induced apoptosis.
findings: []
- id: PMID:16189514
title: Towards a proteome-scale map of the human protein-protein interaction
network.
findings: []
- id: PMID:16754800
title: 'Single-gene mutations and increased left ventricular wall thickness in
the community: the Framingham Heart Study.'
findings: []
- id: PMID:17556658
title: Dilated cardiomyopathy mutant tropomyosin mice develop cardiac
dysfunction with significantly decreased fractional shortening and
myofilament calcium sensitivity.
findings: []
- id: PMID:17721995
title: Role of high-molecular weight tropomyosins in TGF-beta-mediated
control of cell motility.
findings: []
- id: PMID:17987659
title: Nebulette interacts with filamin C.
findings: []
- id: PMID:21516116
title: Next-generation sequencing to generate interactome datasets.
findings: []
- id: PMID:21817107
title: MicroRNA-21 regulates vascular smooth muscle cell function via
targeting tropomyosin 1 in arteriosclerosis obliterans of lower
extremities.
findings: []
- id: PMID:25416956
title: A proteome-scale map of the human interactome network.
findings: []
- id: PMID:25910212
title: Widespread macromolecular interaction perturbations in human genetic
disorders.
findings: []
- id: PMID:26871637
title: Widespread Expansion of Protein Interaction Capabilities by
Alternative Splicing.
findings: []
- id: PMID:30021884
title: Histone Interaction Landscapes Visualized by Crosslinking Mass
Spectrometry in Intact Cell Nuclei.
findings: []
- id: PMID:32296183
title: A reference map of the human binary protein interactome.
findings: []
- id: PMID:3336363
title: 'Human hTM alpha gene: expression in muscle and nonmuscle tissue.'
findings: []
- id: PMID:33961781
title: Dual proteome-scale networks reveal cell-specific remodeling of the
human interactome.
findings: []
- id: PMID:40205054
title: Multimodal cell maps as a foundation for structural and functional
genomics.
findings: []
- id: PMID:8205619
title: 'Alpha-tropomyosin and cardiac troponin T mutations cause familial hypertrophic
cardiomyopathy: a disease of the sarcomere.'
findings: []
- id: Reactome:R-HSA-390593
title: ATP Hydrolysis By Myosin
findings: []
- id: Reactome:R-HSA-390595
title: Calcium Binds Troponin-C
findings: []
- id: Reactome:R-HSA-390597
title: Release Of ADP From Myosin
findings: []
- id: Reactome:R-HSA-390598
title: Myosin Binds ATP
findings: []
- id: Reactome:R-HSA-445699
title: ATP Hydrolysis By Myosin
findings: []
- id: Reactome:R-HSA-445700
title: Myosin Binds ATP
findings: []
- id: Reactome:R-HSA-445704
title: Calcium Binds Caldesmon
findings: []
- id: Reactome:R-HSA-445705
title: Release Of ADP From Myosin
findings: []
alternative_products:
- name: 1 (Skeletal muscle, TPM1alpha)
id: P09493-1
description: >-
The canonical striated muscle isoform (284 AA). Also called TPM1alpha. Expressed
in
skeletal and cardiac muscle where it regulates actin-myosin interaction during
muscle
contraction. Mutations cause familial hypertrophic cardiomyopathy (HCM). GO
annotations
for "muscle contraction" and "sarcomere organization" refer primarily to this
isoform.
- name: 2 (Smooth muscle)
id: P09493-2
sequence_note: VSP_006576, VSP_006578, VSP_006579
description: >-
The smooth muscle-specific isoform. Contains alternative exons that confer smooth
muscle-
specific properties. Regulates contraction in blood vessels, intestine, and
other smooth
muscle tissues. Distinct from striated muscle function of isoform 1.
- name: 3 (Fibroblast, TM3)
id: P09493-3
sequence_note: VSP_006577, VSP_006579
description: >-
A cytoskeletal/non-muscle isoform expressed in fibroblasts. Also called TM3.
Functions
in non-muscle actin cytoskeleton organization rather than muscle contraction.
Regulates
cell morphology, motility, and cytokinesis. GO annotations for "muscle contraction"
do NOT apply to this isoform.
- name: '4'
id: P09493-4
sequence_note: VSP_006577
description: >-
A less characterized isoform. May have cytoskeletal rather than muscle-specific
functions.
- name: '5'
id: P09493-5
sequence_note: VSP_017498, VSP_017499
description: >-
A less characterized isoform. Functional role not well established in the literature.
- name: 6 (10, TPM1kappa)
id: P09493-6
sequence_note: VSP_036064
description: >-
Also called TPM1kappa. A non-muscle/cytoskeletal isoform. Functions in actin
cytoskeleton
organization in non-muscle cells.
- name: '7'
id: P09493-7
sequence_note: VSP_036064, VSP_006579
description: >-
A less characterized isoform with combined features. Functional role not well
established.
- name: '8'
id: P09493-8
sequence_note: VSP_047297, VSP_047298, VSP_047299,
description: >-
A less characterized isoform. Functional role not well established in the literature.
- name: '9'
id: P09493-9
sequence_note: VSP_006579
description: >-
A less characterized isoform. Functional role not well established in the literature.
- name: '10'
id: P09493-10
sequence_note: VSP_047299, VSP_047300, VSP_047301
description: >-
A less characterized isoform. Functional role not well established in the literature.