MTC7 encodes a small, poorly characterized Saccharomyces cerevisiae membrane protein with two predicted transmembrane helices and a basic, disordered C-terminal region. The only direct functional evidence links MTC7 to telomere biology through a genome-wide cdc13-1 genetic interaction screen: mtc7 deletion was placed in a phenotypic class associated with UP-DOWN sensitivity in a telomere uncapping assay and short-telomere clustering. The evidence supports a role in telomere-capping-related biology, but it does not define Mtc7's molecular activity, direct telomere localization, or mechanism.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0016020 membrane | IEA GO_REF:0000120 | ACCEPT | Summary: UniProt annotates Mtc7 as a multi-pass membrane protein, and the sequence contains two predicted transmembrane helices. This is currently the only supported cellular-component annotation in GOA. Reason: The membrane annotation is appropriately broad and is supported by sequence-based transmembrane prediction in UniProt. No stronger compartment-specific experimental localization was found in the current GOA/UniProt-derived files, and no Huh et al. GFP-library compartment call is represented for MTC7 here. Supporting Evidence: UniProt:P32633 SUBCELLULAR LOCATION: Membrane; Multi-pass membrane protein. TRANSMEM features are annotated at residues 13-33 and 42-62. |
| GO:0003674 molecular_function | ND GO_REF:0000015 | ACCEPT | Summary: The ND molecular-function annotation remains appropriate. MTC7 has no demonstrated enzymatic, binding, transporter, or adaptor activity in the accessible literature or Falcon report. Reason: Mtc7 is genetically associated with telomere-capping phenotypes, but no molecular function has been measured. Retaining the ND annotation is more defensible than inferring DNA binding, protein binding, or a telomere structural role. Supporting Evidence: file:yeast/MTC7/MTC7-deep-research-falcon.md No study in the retrieved corpus provides a direct molecular function for Mtc7 (no catalytic reaction, substrate specificity, binding activity, or domain assignment). |
| GO:0005575 cellular_component | ND GO_REF:0000015 | REMOVE | Summary: The generic ND cellular-component placeholder is superseded by the sequence-supported membrane annotation. Reason: GOA already contains the more informative cellular-component term GO:0016020 membrane. No direct evidence supports the previously drafted nucleus annotation. |
| GO:0008150 biological_process | ND GO_REF:0000015 | REMOVE | Summary: The generic ND biological-process placeholder is less informative than the published genetic evidence implicating MTC7 in telomere-capping-related phenotypes. Reason: MTC7 was identified in a cdc13-1 genetic-interaction screen and placed in a phenotypic class associated with UP-DOWN sensitivity and short-telomere clustering, so a telomere-related process annotation is more informative than a root biological_process placeholder. The mechanism remains unresolved and should not be over-specified beyond this process-level association. |
| GO:0016233 telomere capping | IGI | NEW | Summary: A new process annotation to telomere capping is defensible as a conservative interpretation of the cdc13-1 genetic interaction screen and UniProt's "may be involved in telomere capping" function statement. Reason: Addinall et al. identified MTC7 as a previously uncharacterized gene whose deletion genetically interacted with cdc13-1 and was placed in a phenotypic class associated with telomere-uncapping sensitivity and short-telomere clustering. This supports involvement in telomere capping biology, while the review should explicitly avoid claiming a direct molecular role in the CST cap or direct telomere binding. Supporting Evidence: PMID:18845848 We also identified a number of genes of previously unknown function that we term RTC, for restriction of telomere capping, or MTC, for maintenance of telomere capping. file:yeast/MTC7/MTC7-deep-research-falcon.md MTC7 is explicitly described as previously uncharacterized and is implicated in telomere biology by clustering with gene deletions that confer cdc13-1-dependent telomere-capping sensitivity and short telomeres. |
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Download this section (compressed HTML)Q: What molecular activity does Mtc7 carry out, and does it bind a specific telomere-associated protein, membrane complex, RNA, or DNA substrate?
Q: Is Mtc7 physically present at telomeres, at an endomembrane compartment, or does it influence telomere capping indirectly through chromatin or stress response pathways?
Q: Which phenotype of mtc7 deletion is primary: defective telomere capping, altered telomere length maintenance, or a broader membrane-linked stress response that modifies cdc13-1 viability?
Experiment: Measure telomere length, single-stranded telomeric DNA accumulation, and checkpoint activation in mtc7 deletion cells and mtc7 cdc13-1 double mutants across permissive and semi-permissive temperatures.
Type: genetics
Experiment: Determine Mtc7 localization using endogenously tagged, functional Mtc7 combined with membrane markers and telomere-marker ChIP or live-cell imaging assays.
Type: microscopy
Experiment: Identify Mtc7 physical interactors by affinity purification-mass spectrometry under normal and telomere-uncapping stress conditions, followed by validation of candidates from telomere, chromatin, and membrane pathways.
Type: proteomics
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Download this section (compressed HTML)📊 View Pathway Visualization Interactive pathway diagram with detailed annotations