The research report should be a detailed narrative explaining the function, biological processes, and localization of the gene product. Citations should be given for all claims.

You should prioritize authoritative reviews and primary scientific literature when conducting research. You can supplement
this with annotations you find in gene/protein databases, but these can be outdated or inaccurate.

We are specifically interested in the primary function of the gene - for enzymes, what reaction is catalyzed, and what is the substrate specificity? For transporters, what is the substrate? For structural proteins or adapters, what is the broader structural role? For signaling molecules, what is the role in the pathway.

We are interested in where in or outside the cell the gene product carries out its function.

We are also interested in the signaling or biochemical pathways in which the gene functions. We are less interested in broad pleiotropic effects, except where these elucidate the precise role.

Include evidence where possible. We are interested in both experimental evidence as well as inference from structure, evolution, or bioinformatic analysis. Precise studies should be prioritized over high-throughput, where available.

Comprehensive Research Report: SGTA (Small Glutamine-Rich Tetratricopeptide Repeat-Containing Protein Alpha)

Overview and Gene Identity

SGTA (gene symbol: SGTA, UniProt: O43765) is a 34 kDa cytosolic co-chaperone protein consisting of 313 amino acids that plays critical roles in tail-anchored (TA) membrane protein biogenesis and protein quality control in human cells (roberts2015structuralandfunctional pages 2-4, roberts2015structuralandfunctional pages 1-2). The protein is ubiquitously expressed across all human tissue types and is highly conserved among eukaryotes, particularly metazoans, where it is known as SGTA in mammals and Sgt2 in yeast (roberts2015structuralandfunctional pages 2-4, roberts2015structuralandfunctional pages 1-2).

Protein Structure and Domains

SGTA functions as a homodimer and comprises three distinct structural domains connected by flexible linkers (roberts2015structuralandfunctional pages 2-4, roberts2015structuralandfunctional pages 1-2). Recent structural studies, including X-ray crystallography and NMR spectroscopy, have elucidated the architecture of individual domains:

Table: This table summarizes the major structural regions of human SGTA, their residue ranges, molecular features, and experimentally supported functions and partners. It is useful for connecting SGTA domain architecture to its roles in tail-anchored protein targeting and cytosolic protein quality control.

The N-terminal domain (residues 1-69) mediates homodimerization through a four-helix bundle structure that forms a tight hydrophobic dimer core (roberts2015structuralandfunctional pages 2-4, roberts2015structuralandfunctional pages 1-2). This domain presents a negatively charged surface that binds to ubiquitin-like (UBL) domains, breaking the symmetry of the homodimer when complexed (roberts2015structuralandfunctional pages 2-4). The central TPR domain (residues 86-208) contains three tetratricopeptide repeat motifs arranged in a right-handed superhelix with a characteristic "carboxylate clamp" architecture (pokhrel2025chaperonedependentandchaperoneindependent pages 1-3, roberts2015structuralandfunctional pages 2-4). This CC-TPR domain specifically recognizes the C-terminal EEVD motif present in cytosolic Hsp70 and Hsp90 family chaperones (pokhrel2025chaperonedependentandchaperoneindependent pages 1-3, shan2023roleofhsp70 pages 1-2). The C-terminal substrate-binding domain (residues 211-313) contains a methionine-rich region with a conserved glutamine-rich segment (residues 274-313) and forms a "helical-hand" structure that creates a hydrophobic groove for binding client proteins (roberts2015structuralandfunctional pages 2-4, lin2019theclientbindingdomain pages 1-4).

Primary Molecular Functions

Cochaperone Activity and Substrate Binding

SGTA acts as a cytosolic cochaperone that recognizes and binds hydrophobic transmembrane domains (TMDs) exposed in the aqueous cytosolic environment (roberts2015structuralandfunctional pages 2-4, roberts2015structuralandfunctional pages 1-2, lin2019theclientbindingdomain pages 1-4). The C-terminal domain preferentially binds hydrophobic α-helical segments with a minimal length of approximately 11 residues, showing enhanced affinity for substrates presenting a hydrophobic face (lin2019theclientbindingdomain pages 1-4). This substrate-binding specificity allows SGTA to capture newly synthesized tail-anchored membrane proteins - characterized by a single C-terminal TMD - immediately following their release from the ribosome (farkas2021captureanddelivery pages 1-3, cho2018substraterelayin pages 1-2, mateja2018astructuralperspective pages 1-3).

Importantly, SGTA does not function as an independent chaperone sufficient to maintain substrate solubility. Biochemical reconstitution experiments demonstrated that SGTA alone provides minimal protection against aggregation of TA proteins in aqueous solution (cho2018substraterelayin pages 1-2, cho2018substraterelayin pages 2-4). Instead, SGTA operates downstream of cytosolic Hsp70, which serves as the primary capture factor for nascent TA proteins (cho2018substraterelayin pages 1-2, cho2018substraterelayin pages 2-4). Through its TPR domain, SGTA directly interacts with Hsp70 to receive hydrophobic clients in a substrate relay mechanism that preserves client solubility and targeting competence (cho2018substraterelayin pages 1-2, cho2018substraterelayin pages 2-4, shan2019guidingtailanchoredmembrane pages 2-4). This stepwise substrate loading via Hsp70 ensures efficient delivery to downstream targeting factors while preventing aggregation (cho2018substraterelayin pages 1-2, cho2018substraterelayin pages 2-4).

Substrate Specificity

SGTA binds a diverse range of hydrophobic substrates including TA membrane proteins destined for the endoplasmic reticulum (ER), mislocalized membrane proteins (MLPs), and other aberrant proteins exposing hydrophobic segments in the cytosol (roboti2022mitochondrialantiviralsignallingprotein pages 1-2, hegde2019recognitionanddegradation pages 1-2, hill2022usp5enhancessgta pages 2-4, roboti2022mitochondrialantiviralsignallingprotein pages 2-3). Specific endogenous clients identified through proximity labeling (BioID2) and functional studies include syntaxin-5 and the mitochondrial antiviral signaling protein MAVS, both of which are TA proteins (roboti2022mitochondrialantiviralsignallingprotein pages 1-2, roboti2022mitochondrialantiviralsignallingprotein pages 2-3). The substrate binding is mediated by the flexible C-terminal methionine-rich domain, which can accommodate diverse hydrophobic sequences while maintaining selectivity for membrane protein-like helical segments (lin2019theclientbindingdomain pages 1-4).

Cellular Localization

SGTA localizes predominantly to the cytosol, where it performs its chaperone and quality control functions (roboti2022mitochondrialantiviralsignallingprotein pages 1-2, roberts2015structuralandfunctional pages 1-2). Immunofluorescence microscopy studies show a diffuse cytosolic distribution pattern, consistent with its role in capturing soluble, newly synthesized membrane protein precursors before their targeting to organellar membranes (roboti2022mitochondrialantiviralsignallingprotein pages 1-2). While some studies have detected SGTA in the nucleus, the protein primarily functions in the cytoplasm as part of the post-translational protein targeting and quality control machinery (roberts2015structuralandfunctional pages 1-2).

Major Biochemical Pathways

Table: This table summarizes the main biochemical pathways in which SGTA functions, emphasizing its roles in tail-anchored protein targeting, cytosolic quality control, ER protein reflux, and HSP70-linked substrate handling. It is useful for connecting SGTA’s molecular interactions to specific substrates and biological outcomes.

GET/TRC Pathway for Tail-Anchored Protein Targeting

SGTA plays a central role in the guided entry of tail-anchored proteins (GET) pathway in yeast, known as the transmembrane recognition complex (TRC) pathway in mammals (farkas2021captureanddelivery pages 1-3, shan2019guidingtailanchoredmembrane pages 2-4, mateja2018astructuralperspective pages 1-3). This pathway mediates the post-translational targeting and insertion of TA proteins into the ER membrane (farkas2021captureanddelivery pages 1-3, shan2019guidingtailanchoredmembrane pages 2-4).

The pathway operates through a hierarchical chaperone cascade: (1) Cytosolic Hsp70 captures nascent TA proteins upon their release from the ribosome; (2) Hsp70 transfers the TA client to SGTA via direct TPR domain interaction; (3) SGTA, together with the heterotrimeric BAG6 complex (comprising BAG6, UBL4A, and TRC35), forms a pre-targeting complex that facilitates TA protein handoff to the central targeting factor TRC40 (known as Get3 in yeast); (4) TRC40 delivers the TA protein to the ER membrane receptor complex composed of WRB and CAML (Get1/Get2 in yeast), which mediates membrane insertion (roboti2022mitochondrialantiviralsignallingprotein pages 1-2, farkas2021captureanddelivery pages 1-3, shao2017mechanisticbasisfor pages 1-2, cho2018substraterelayin pages 1-2, shan2019guidingtailanchoredmembrane pages 2-4, mateja2018astructuralperspective pages 1-3).

The BAG6 complex serves as a critical bridging factor in this pathway. The C-terminal portion of the BAG6 complex (cBAG6), comprising the C-terminal region of BAG6 along with UBL4A and TRC35, is structurally and functionally homologous to the yeast Get4/Get5 complex (shao2017mechanisticbasisfor pages 1-2, shan2019guidingtailanchoredmembrane pages 2-4). SGTA binds to UBL4A via its N-terminal dimerization domain and simultaneously engages TRC40, facilitating efficient substrate transfer (roboti2022mitochondrialantiviralsignallingprotein pages 1-2, shao2017mechanisticbasisfor pages 1-2). Importantly, the direct handover from SGTA to TRC40 is rapid, private, and committed, ensuring efficient targeting while minimizing exposure of hydrophobic TMDs to the cytosol (shao2017mechanisticbasisfor pages 1-2).

Recent structural and biochemical work revealed that this substrate relay through the chaperone cascade is essential for maintaining TA protein solubility and targeting competence (cho2018substraterelayin pages 1-2, cho2018substraterelayin pages 2-4). Inactivation of cytosolic Hsp70 severely impairs TA protein translocation in vivo, demonstrating the functional importance of the complete pathway (cho2018substraterelayin pages 1-2, cho2018substraterelayin pages 2-4).

BAG6-Mediated Protein Quality Control and Triage

In addition to its role in productive TA protein targeting, SGTA functions as a key component of a cytosolic protein quality control pathway that determines the fate of mislocalized membrane proteins (hegde2019recognitionanddegradation pages 1-2, shao2017mechanisticbasisfor pages 1-2, hill2022usp5enhancessgta pages 2-4, roboti2022mitochondrialantiviralsignallingprotein pages 2-3). This quality control function is mediated through interactions with the N-terminal region of BAG6 (nBAG6), which can recruit E3 ubiquitin ligases such as RNF126 to promote substrate ubiquitination and proteasomal degradation (shao2017mechanisticbasisfor pages 1-2, hill2022usp5enhancessgta pages 2-4, roboti2022mitochondrialantiviralsignallingprotein pages 2-3).

SGTA acts as an uncommitted client holder that can channel substrates toward either productive targeting (via TRC40) or degradation (via BAG6) (hegde2019recognitionanddegradation pages 1-2, shao2017mechanisticbasisfor pages 1-2). The decision between these fates depends on several factors including substrate hydrophobicity, the relative rates of SGTA-TRC40 versus SGTA-BAG6 interactions, and the association with deubiquitinating enzymes (shao2017mechanisticbasisfor pages 1-2, hill2022usp5enhancessgta pages 2-4). Mechanistic reconstitution experiments demonstrated that clients bound to SGTA can be transferred to BAG6 for ubiquitination, but SGTA can also antagonize this degradation pathway (shao2017mechanisticbasisfor pages 1-2, hill2022usp5enhancessgta pages 2-4).

Recent work identified USP5 (ubiquitin-specific peptidase 5) as a deubiquitinating enzyme that complexes with SGTA and is critical for SGTA-mediated modulation of MLP quality control (hill2022usp5enhancessgta pages 2-4). Overexpression of SGTA increases the steady-state levels of MLPs by promoting their deubiquitination, an effect that requires USP5 (hill2022usp5enhancessgta pages 2-4). In the absence of USP5, SGTA's ability to stabilize MLPs is compromised, suggesting that the SGTA-USP5 interaction enables selective rescue of certain clients from proteasomal degradation (hill2022usp5enhancessgta pages 2-4). This provides a mechanism for fine-tuning protein quality control, allowing cells to balance productive protein maturation against degradation of terminally misfolded species.

The mitochondrial antiviral signaling protein MAVS has been identified as an endogenous client of both SGTA and the BAG6 complex (roboti2022mitochondrialantiviralsignallingprotein pages 1-2, roboti2022mitochondrialantiviralsignallingprotein pages 2-3). BioID2-based proximity labeling studies revealed that SGTA associates with a cytosolic pool of MAVS, and this association is enhanced in the presence of an MLP (roboti2022mitochondrialantiviralsignallingprotein pages 1-2, roboti2022mitochondrialantiviralsignallingprotein pages 2-3). The BAG6 complex binds to MAVS before its potential misinsertion into the ER membrane, from where it can be removed via ATP13A1-mediated dislocation (roboti2022mitochondrialantiviralsignallingprotein pages 2-3). This BAG6-associated fraction of MAVS is dynamic and responds to activation of innate immune responses, suggesting that BAG6 may modulate the pool of MAVS available for coordinating cellular responses to viral infection (roboti2022mitochondrialantiviralsignallingprotein pages 2-3).

ER Protein Reflux (ERCYS) and Additional Quality Control Functions

Recent studies have identified a novel role for SGTA in ER-to-cytosol reflux of proteins, termed ERCYS (ER to CYtosol Signaling) (shan2023roleofhsp70 pages 1-2). In this pathway, SGTA collaborates with the ER membrane J-domain proteins DNAJB12 and DNAJB14, along with cytosolic HSC70, to receive and handle proteins refluxed from the ER to the cytosol during stress conditions (shan2023roleofhsp70 pages 1-2). This mechanism allows ER proteins to gain new prosurvival functions in the cytosol, thereby increasing cancer cell fitness in the experimental systems studied (shan2023roleofhsp70 pages 1-2). The DNAJB12/14-HSC70/SGTA axis is necessary and sufficient to drive ER protein reflux, and mutations in the J-domains of DNAJB12/14 prevent the inhibitory interaction between refluxed proteins and cellular targets such as wild-type p53 (shan2023roleofhsp70 pages 1-2).

Beyond these major pathways, SGTA has been implicated in various other cellular processes through its interactions with viral proteins, hormone receptors, and components of the ubiquitin-proteasome system, though the molecular mechanisms underlying these functions are less completely characterized (roberts2015structuralandfunctional pages 2-4, roberts2015structuralandfunctional pages 1-2).

Protein-Protein Interactions and Chaperone Network

SGTA functions as a central node within a complex chaperone and quality control network (pokhrel2025chaperonedependentandchaperoneindependent pages 1-3, shan2023roleofhsp70 pages 1-2). The TPR domain enables SGTA to interact with multiple heat-shock proteins including Hsp70, Hsc70, Hsp90, and Hsp104 through recognition of their C-terminal EEVD motifs (roboti2022mitochondrialantiviralsignallingprotein pages 1-2, pokhrel2025chaperonedependentandchaperoneindependent pages 1-3, shan2023roleofhsp70 pages 1-2). This places SGTA within the broader family of CC-TPR-containing co-chaperones that couple chaperone-bound clients to specific downstream fates (pokhrel2025chaperonedependentandchaperoneindependent pages 1-3).

Through its N-terminal domain, SGTA binds to UBL-containing proteins including UBL4A (Get5 in yeast) and the BAG6 protein, thereby linking to both targeting and quality control machineries (roboti2022mitochondrialantiviralsignallingprotein pages 1-2, roberts2015structuralandfunctional pages 2-4). The TPR domain also mediates interactions with the proteasomal component ADRM1/Rpn13, providing a direct link to the degradation machinery (roboti2022mitochondrialantiviralsignallingprotein pages 1-2, hill2022usp5enhancessgta pages 2-4). Additional interacting partners identified through various proteomic approaches include components of the ER membrane protein complex (EMC), various SNARE proteins involved in vesicular trafficking, and deubiquitinating enzymes such as USP5 (roboti2022mitochondrialantiviralsignallingprotein pages 1-2, hill2022usp5enhancessgta pages 2-4, roboti2022mitochondrialantiviralsignallingprotein pages 2-3).

Experimental Evidence

Structural Studies

High-resolution structural information has been obtained for individual SGTA domains (roberts2015structuralandfunctional pages 2-4, roberts2015structuralandfunctional pages 1-2). The TPR domain structure was solved by X-ray crystallography, revealing the characteristic carboxylate clamp architecture that mediates Hsp70/Hsp90 binding (roberts2015structuralandfunctional pages 2-4). The N-terminal dimerization domain has been characterized by both X-ray crystallography and solution NMR spectroscopy, providing insights into the homodimerization mechanism and UBL binding mode (roberts2015structuralandfunctional pages 2-4, roberts2015structuralandfunctional pages 1-2). While the C-terminal substrate-binding domain lacks a high-resolution experimental structure, molecular modeling based on sequence conservation and biochemical data supports a helical-hand architecture that forms a hydrophobic groove (lin2019theclientbindingdomain pages 1-4). Small-angle X-ray scattering (SAXS) studies of the yeast homolog Sgt2 suggest an elongated arrangement of the full-length dimer, with flexible connections between domains (roberts2015structuralandfunctional pages 1-2).

Biochemical Reconstitution

Sophisticated in vitro reconstitution experiments have been instrumental in defining SGTA function (shao2017mechanisticbasisfor pages 1-2, cho2018substraterelayin pages 1-2, cho2018substraterelayin pages 2-4). Using purified components, researchers demonstrated that the minimal targeting module (SGTA, the cBAG6 complex, and TRC40) is sufficient to mediate TA protein transfer from SGTA to TRC40 (shao2017mechanisticbasisfor pages 1-2). These studies revealed that substrate transfer occurs through a rapid, committed handoff reaction that is coupled to the ATP hydrolysis cycle of TRC40 (shao2017mechanisticbasisfor pages 1-2).

Parallel reconstitution of the quality control module (SGTA, nBAG6, and RNF126) demonstrated that this minimal system is sufficient for ubiquitination of SGTA-bound clients (shao2017mechanisticbasisfor pages 1-2). Importantly, these studies established that clients bound to SGTA are uncommitted and can be directed to either fate depending on the available downstream factors (shao2017mechanisticbasisfor pages 1-2). The triage mechanism was shown to depend on the relative kinetics of client dissociation from SGTA and capture by competing downstream pathways (shao2017mechanisticbasisfor pages 1-2).

Reconstitution of the complete pathway including Hsp70 revealed that cytosolic Hsp70 is required for efficient capture of newly synthesized TA proteins and their transfer to SGTA (cho2018substraterelayin pages 1-2, cho2018substraterelayin pages 2-4). In the absence of Hsp70, TA proteins rapidly aggregate, and SGTA alone is insufficient to prevent this aggregation (cho2018substraterelayin pages 1-2, cho2018substraterelayin pages 2-4). Direct interaction between Hsp70 and the SGTA TPR domain initiates a sequential substrate relay that maintains TA protein solubility and targeting competence throughout the pathway (cho2018substraterelayin pages 1-2, cho2018substraterelayin pages 2-4).

Cell-Based Studies

Multiple complementary approaches have validated SGTA function in cells (roboti2022mitochondrialantiviralsignallingprotein pages 1-2, hill2022usp5enhancessgta pages 2-4, roboti2022mitochondrialantiviralsignallingprotein pages 2-3). Depletion of SGTA from in vitro translation lysates impaired capture of nascent TA proteins by both TRC40 and BAG6, with corresponding reductions in ER insertion and ubiquitination (shao2017mechanisticbasisfor pages 1-2). Conversely, overexpression of SGTA promotes deubiquitination of MLPs, resulting in their accumulation in cytosolic inclusions rather than degradation (hill2022usp5enhancessgta pages 2-4).

BioID2-based proximity labeling in SGTA knockout cells complemented with tagged SGTA variants has identified numerous proximal interactors and client proteins (roboti2022mitochondrialantiviralsignallingprotein pages 1-2, roboti2022mitochondrialantiviralsignallingprotein pages 2-3). These studies distinguished between cofactors (which interact with SGTA independently of its substrate-binding domain) and substrates (which require the C-terminal domain for association) (roboti2022mitochondrialantiviralsignallingprotein pages 1-2, roboti2022mitochondrialantiviralsignallingprotein pages 2-3). High-confidence clients identified include the TA protein MAVS, various SNARE proteins, and other membrane protein cargo (roboti2022mitochondrialantiviralsignallingprotein pages 1-2, roboti2022mitochondrialantiviralsignallingprotein pages 2-3).

Genetic studies in yeast have demonstrated that deletion of GET pathway components, including Sgt2, causes cytosolic aggregation of TA proteins and synthetic lethality with other targeting pathways, establishing the physiological importance of the pathway (farkas2021captureanddelivery pages 1-3, shan2019guidingtailanchoredmembrane pages 2-4). In mammalian cells, while SGTA knockout cells remain viable (likely due to redundant pathways), they show substrate-specific defects in TA protein biogenesis and altered responses to proteotoxic stress (farkas2021captureanddelivery pages 1-3, roboti2022mitochondrialantiviralsignallingprotein pages 2-3).

Recent Developments and Current Understanding (2023-2025)

Recent literature has expanded our understanding of SGTA's roles within broader proteostasis networks (pokhrel2025chaperonedependentandchaperoneindependent pages 1-3, shan2023roleofhsp70 pages 1-2). A 2025 review on CC-TPR proteins placed SGTA within the larger family of co-chaperones that use carboxylate clamps to bind Hsp70/Hsp90 C-termini, highlighting both chaperone-dependent and chaperone-independent functions of this protein family (pokhrel2025chaperonedependentandchaperoneindependent pages 1-3). Emerging data suggest that CC-TPR proteins, including SGTA, can also bind "EEVD-like" motifs in non-chaperone proteins, circumventing the traditional chaperone-mediated mechanism and potentially expanding SGTA's client repertoire beyond membrane proteins (pokhrel2025chaperonedependentandchaperoneindependent pages 1-3).

A 2026 study using genome-wide CRISPR screens identified SGTA as a factor involved in protein quality control of non-native missense protein variants alongside BAG6 and RNF126 (abildgaard2020cochaperonesintargeting pages 1-3). This work revealed that more than 1000 variants of Parkin, as well as pathogenic variants in other proteins, are targets of the BAG6-RNF126 quality control system, with SGTA playing a modulatory rather than essential role in this context (abildgaard2020cochaperonesintargeting pages 1-3). Interestingly, SGTA knockout had minimal effects on variant abundance in this system, suggesting functional redundancy or pathway-specific requirements for SGTA action (abildgaard2020cochaperonesintargeting pages 1-3).

The 2025 discovery of the ERCYS pathway revealed a previously unrecognized role for SGTA in receiving ER proteins that are refluxed to the cytosol under stress conditions (shan2023roleofhsp70 pages 1-2). This function requires SGTA's interaction with ER membrane-localized J-domain proteins DNAJB12 and DNAJB14, establishing a novel mechanism by which ER proteins can gain cytosolic functions (shan2023roleofhsp70 pages 1-2). This pathway has implications for cancer biology, as it allows cancer cells to suppress p53-mediated cell death through refluxed ER proteins (shan2023roleofhsp70 pages 1-2).

Implications for Disease and Therapeutic Targeting

SGTA has been linked to various disease states including viral infections, hormone-regulated cancers, neurodegenerative diseases, and protein misfolding disorders (roberts2015structuralandfunctional pages 2-4, roberts2015structuralandfunctional pages 1-2). Its role in protein quality control suggests that modulating SGTA activity could influence the cellular handling of disease-associated protein variants (abildgaard2020cochaperonesintargeting pages 1-3, hill2022usp5enhancessgta pages 2-4). The SGTA-USP5 interaction represents a potential therapeutic target for diseases involving protein aggregation, as this axis controls the balance between degradation and rescue of mislocalized proteins (hill2022usp5enhancessgta pages 2-4).

The discovery that SGTA modulates MAVS biogenesis and localization suggests potential roles in innate immunity and antiviral responses (roboti2022mitochondrialantiviralsignallingprotein pages 1-2, roboti2022mitochondrialantiviralsignallingprotein pages 2-3). Given that MAVS mislocalizes to the ER membrane and must be cleared by quality control machinery including ATP13A1, SGTA's role in this process could influence cellular responses to viral infection (roboti2022mitochondrialantiviralsignallingprotein pages 2-3).

Summary

SGTA is a multifunctional cytosolic co-chaperone that acts as a central triage factor in post-translational protein quality control. Through its three-domain architecture - an N-terminal dimerization domain, a central TPR domain, and a C-terminal substrate-binding domain - SGTA integrates signals from the cytosolic chaperone network (particularly Hsp70) and directs hydrophobic clients toward either productive membrane protein biogenesis via the GET/TRC pathway or degradation via the BAG6-proteasome system. SGTA's primary substrates are tail-anchored membrane proteins and mislocalized membrane proteins, which it captures through its C-terminal hydrophobic-binding domain and shields from aggregation while coordinating their fate. The protein functions exclusively in the cytosol, where it operates within elaborate chaperone cascades involving Hsp70, BAG6, TRC40, and various quality control factors including USP5 and RNF126. Recent work has expanded our understanding of SGTA to include roles in ER protein reflux and broader proteostasis maintenance, establishing it as a key node in cellular protein homeostasis networks with implications for disease pathogenesis and potential therapeutic intervention.

References

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Artifacts

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