Hsc70 Protein

Hsc70 Protein

Introduction

<table class="infobox infobox-protein">
<tr>
<th class="infobox-header" colspan="2">Hsc70 Protein</th>
</tr>
<tr>
<td class="label">Symbol</td>
<td><strong>HSPA8</strong></td>
</tr>
<tr>
<td class="label">Full Name</td>
<td>Hsc70</td>
</tr>
<tr>
<td class="label">Type</td>
<td>Protein</td>
</tr>
<tr>
<td class="label">UniProt</td>
<td><a href="https://www.uniprot.org/uniprot/?query=HSPA8" target="_blank">Search UniProt</a></td>
</tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/als" style="color:#ef9a9a">ALS</a>, <a href="/wiki/als" style="color:#ef9a9a">Als</a>, <a href="/wiki/alzheimer" style="color:#ef9a9a">Alzheimer</a>, <a href="/wiki/amyotrophic-lateral-sclerosis" style="color:#ef9a9a">Amyotrophic Lateral Sclerosis</a>, <a href="/wiki/ataxia" style="color:#ef9a9a">Ataxia</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">326 edges</a></td>
</tr>
</table>

Pathway Diagram

Hsc70 Protein

Introduction

<table class="infobox infobox-protein">
<tr>
<th class="infobox-header" colspan="2">Hsc70 Protein</th>
</tr>
<tr>
<td class="label">Symbol</td>
<td><strong>HSPA8</strong></td>
</tr>
<tr>
<td class="label">Full Name</td>
<td>Hsc70</td>
</tr>
<tr>
<td class="label">Type</td>
<td>Protein</td>
</tr>
<tr>
<td class="label">UniProt</td>
<td><a href="https://www.uniprot.org/uniprot/?query=HSPA8" target="_blank">Search UniProt</a></td>
</tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/als" style="color:#ef9a9a">ALS</a>, <a href="/wiki/als" style="color:#ef9a9a">Als</a>, <a href="/wiki/alzheimer" style="color:#ef9a9a">Alzheimer</a>, <a href="/wiki/amyotrophic-lateral-sclerosis" style="color:#ef9a9a">Amyotrophic Lateral Sclerosis</a>, <a href="/wiki/ataxia" style="color:#ef9a9a">Ataxia</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">326 edges</a></td>
</tr>
</table>

Pathway Diagram

Hsc70 Protein is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.

{"content": "# Hsc70 Protein (HSPA8)\n\n<div class=\"infobox infobox-protein\">\n <table>\n <tr><th colspan=\"2\" style=\"background:#4a90d9; color:white;\">Hsc70 (Heat Shock Protein 70 Cognate)</th></tr>\n <tr><td><strong>Gene</strong></td><td><a href=\"/genes/hspa8\">HSPA8</a></td></tr>\n <tr><td><strong>UniProt ID</strong></td><td><a href=\"https://www.uniprot.org/uniprot/P11142\">P11142</a></td></tr>\n <tr><td><strong>Molecular Weight</strong></td><td>71 kDa</td></tr>\n <tr><td><strong>Subcellular Localization</strong></td><td>Cytoplasm, nucleus, organelles</td></tr>\n <tr><td><strong>Protein Family</strong></td><td>Hsp70 family</td></tr>\n </table>\n</div>\n\n\n## Overview\n\nHsc70 (Heat Shock Cognate 70 kDa Protein / HSPA8) is a constitutively expressed molecular chaperone that plays essential roles in protein folding, refolding, and degradation["^1"]. It is a member of the Hsp70 family and is crucial for cellular proteostasis.\n\n## Structure\n\nHsc70 contains multiple functional domains:\n\n1. N-terminal ATPase domain (45 kDa): Binds and hydrolyzes ATP, regulating substrate binding\n2. Substrate-binding domain (25 kDa): Binds hydrophobic peptide segments\n3. C-terminal domain (10 kDa): Lid that covers the substrate-binding pocket\n\n## Normal Function\n\nHsc70 performs essential cellular functions:\n\n- Protein folding: Assists nascent proteins to attain proper conformation\n- Protein refolding: Rescues stress-damaged proteins\n- Protein degradation: Cooperates with the proteasome and autophagy machinery\n- Clathrin uncoating: Essential for synaptic vesicle recycling\n- Nuclear import: Facilitates protein transport through nuclear pores\n- [Autophagy](/entities/autophagy): LC3-interacting protein (LIR) mediates selective autophagy\n\n## Role in Disease\n\n### Alzheimer's Disease\n\n- Hsc70 chaperone activity declines with age\n- Impaired A\u03b2 clearance through autophagy\n- Modulates [tau](/proteins/tau) aggregation and clearance\n- Genetic variants affect AD risk\n\n### Parkinson's Disease\n\n- Essential for \u03b1-synuclein clearance\n- Hsc70 enhancers show therapeutic potential\n- Involved in mitophagy through selective autophagy\n\n### ALS\n\n- Mutant SOD1 clearance depends on Hsc70\n- Impaired protein homeostasis in motor [neurons](/entities/neurons)\n- Therapeutic target for small molecule activators\n\n### Huntington's Disease\n\n- Mutant [huntingtin](/proteins/huntingtin-protein) clearance requires Hsc70\n- Co-chaperone partnerships modulate clearance efficiency\n- HSP70 gene polymorphisms affect disease onset\n\n## Therapeutic Targeting\n\n| Approach | Mechanism | Status |\n|----------|-----------|--------|\n| 2-phenylethynesulfonamide (PES) | Hsc70 inhibitor | Research |\n| HSPA8-targeted small molecules | Modulate chaperone activity | Preclinical |\n| Gene therapy | Increase Hsc70 expression | Research |\n\n## Research Directions\n\nCurrent research explores:\n- Developing brain-penetrant Hsc70 modulators\n- Understanding co-chaperone specificity\n- Targeting Hsc70 for neurodegenerative disease therapy\n\n

Brain Atlas Resources

• [Allen Human Brain Atlas - HSPA8 Expression](https://human.brain-map.org/microarray/search/show?search_term=HSPA8): Gene expression data across brain regions
• [Allen Cell Type Atlas](https://celltypes.brain-map.org/): Cellular expression patterns in neurons and glia
• [BrainSpan - HSPA8 Developmental Expression](https://brainspan.org/): Developmental transcriptome data
• [Allen Mouse Brain Atlas](https://mouse.brain-map.org/): Mouse brain expression data

References\n\n[^1]: ^{<a href=\"https://pubmed.ncbi.nlm.nih.gov/12627322/\">[1]</a>} Mayer MP, et al. Hsp70 chaperone function. Adv Protein Chem. 2001.\n\n[^2]: ^{<a href=\"https://pubmed.ncbi.nlm.nih.gov/14676537/\">[2]</a>} Bukau B, et al. Molecular chaperones and protein folding. Cell. 2006.\n\n[^3]: ^{<a href=\"https://pubmed.ncbi.nlm.nih.gov/21872611/\">[3]</a>} Cleva RM, et al. Hsc70 in neurodegeneration. Neuropharmacology. 2011.\n\n[^4]: ^{<a href=\"https://pubmed.ncbi.nlm.nih.gov/23480871/\">[4]</a>} Pratt WB, et al. Hsp90 and Hsp70 chaperone machines. J Biol Chem. 2014.\n\n[^5]: ^{<a href=\"https://pubmed.ncbi.nlm.nih.gov/27069067/\">[5]</a>} Liu J, et al. Hsc70 targeting in neurodegenerative disease. Front Cell Neurosci. 2016.\n\n\n## See Also\n\n- Mitochondrial Dynamics\n- Autophagy-Lysosomal Pathway\n- Apoptosis Pathway\n- Alzheimer's Disease\n- Parkinson's Disease\n- Amyotrophic Lateral Sclerosis\n- Huntington's Disease\n- Dynamin Proteins\n\n## External Links\n\n- [UniProt: DRP1](https://www.uniprot.org/uniprot/O00429)\n- [PDB: 3W6N](https://www.rcsb.org/structure/3W6N)\n- [GeneCards: DNM1L](https://www.genecards.org/cgi-bin/carddisp.pl?gene=DNM1L)\n\n\n## See Also\n\n- HSPA8 Gene\n- HSP70 Family\n- Protein Quality Control\n- Chaperone Therapy\n\n## External Links\n\n- [UniProt](https://www.uniprot.org/uniprot/P11142)\n- [NCBI Gene](https://www.ncbi.nlm.nih.gov/gene/3312)", "id": 3457, "title": "Hsc70 Protein"}

Overview

Hsc70 (Heat Shock Cognate 70 kDa Protein / HSPA8) is a constitutively expressed molecular chaperone that plays essential roles in protein folding, refolding, and degradation within neuronal cells. As a member of the Hsp70 family, Hsc70 is crucial for maintaining cellular proteostasis and is particularly important in the context of neurodegenerative diseases, where protein aggregation is a hallmark feature.

Molecular Mechanisms

Hsc70 (Heat Shock Cognate 70 kDa protein), also known as HSPA8, is a constitutively expressed molecular chaperone that plays essential roles in protein folding, refolding, and degradation. Unlike inducible Hsp70 (HSPA1A), Hsc70 is expressed at high levels under normal conditions and is upregulated during stress.

Hsc70 participates in multiple cellular processes, including: (1) co-translational protein folding, (2) refolding of stress-denatured proteins, (3) targeting misfolded proteins for degradation via the proteasome or autophagy, (4) disassembly of protein complexes, and (5) assisting translocation of proteins across membranes.

In the nervous system, Hsc70 is particularly important for synaptic function, where it helps maintain the pool of properly folded synaptic proteins and facilitates synaptic vesicle recycling.

Disease Associations

Alzheimer's Disease: Hsc70 is involved in clearing amyloid-beta aggregates and tau phosphorylated species. The protein can target these pathological proteins for autophagic degradation. Hsc70 levels are altered in AD brains, and the protein colocalizes with amyloid plaques and neurofibrillary tangles.

Parkinson's Disease: Hsc70 plays a critical role in clearing alpha-synuclein aggregates through chaperone-mediated autophagy (CMA). Mutations affecting Hsc70 function or expression may contribute to PD pathogenesis. The protein is also involved in mitochondrial quality control.

Huntington's Disease: Hsc70 helps clear mutant huntingtin aggregates and may have neuroprotective effects. The protein interacts with the autophagy machinery to target misfolded proteins for degradation.

ALS: Hsc70 is involved in clearing TDP-43 and FUS aggregates, which are characteristic of ALS pathology. The protein may have therapeutic potential for enhancing aggregate clearance.

Therapeutic Implications

Hsc70 activators are being explored as potential therapies for neurodegenerative diseases. Small molecules that enhance Hsc70 activity could boost clearance of toxic protein aggregates. Conversely, Hsc70 inhibitors may have applications in certain contexts where reducing chaperone activity could promote apoptosis in diseased cells.

Research Directions

Research is focused on developing brain-penetrant Hsc70 modulators and understanding the specific pathways through which Hsc70 clears disease-related proteins. Gene therapy approaches to increase Hsc70 expression are also being explored.

Molecular Mechanisms

Hsc70 (Heat Shock Cognate 70 kDa protein), also known as HSPA8, is a constitutively expressed molecular chaperone that plays essential roles in protein folding, refolding, and degradation. Unlike inducible Hsp70 (HSPA1A), Hsc70 is expressed at high levels under normal conditions and is upregulated during stress.

Hsc70 participates in multiple cellular processes, including: (1) co-translational protein folding, (2) refolding of stress-denatured proteins, (3) targeting misfolded proteins for degradation via the proteasome or autophagy, (4) disassembly of protein complexes, and (5) assisting translocation of proteins across membranes.

In the nervous system, Hsc70 is particularly important for synaptic function, where it helps maintain the pool of properly folded synaptic proteins and facilitates synaptic vesicle recycling.

Disease Associations

Alzheimer's Disease: Hsc70 is involved in clearing amyloid-beta aggregates and tau phosphorylated species. The protein can target these pathological proteins for autophagic degradation. Hsc70 levels are altered in AD brains, and the protein colocalizes with amyloid plaques and neurofibrillary tangles.

Parkinson's Disease: Hsc70 plays a critical role in clearing alpha-synuclein aggregates through chaperone-mediated autophagy (CMA). Mutations affecting Hsc70 function or expression may contribute to PD pathogenesis. The protein is also involved in mitochondrial quality control.

Huntington's Disease: Hsc70 helps clear mutant huntingtin aggregates and may have neuroprotective effects. The protein interacts with the autophagy machinery to target misfolded proteins for degradation.

ALS: Hsc70 is involved in clearing TDP-43 and FUS aggregates, which are characteristic of ALS pathology. The protein may have therapeutic potential for enhancing aggregate clearance.

Therapeutic Implications

Hsc70 activators are being explored as potential therapies for neurodegenerative diseases. Small molecules that enhance Hsc70 activity could boost clearance of toxic protein aggregates. Conversely, Hsc70 inhibitors may have applications in certain contexts where reducing chaperone activity could promote apoptosis in diseased cells.

Research Directions

Research is focused on developing brain-penetrant Hsc70 modulators and understanding the specific pathways through which Hsc70 clears disease-related proteins. Gene therapy approaches to increase Hsc70 expression are also being explored.

Background

The study of Hsc70 Protein has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.

Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.

Brain Atlas Resources

• [Allen Human Brain Atlas - HSPA8 Expression](https://human.brain-map.org/microarray/search/show?search_term=HSPA8): Gene expression data across brain regions
• [Allen Cell Type Atlas](https://celltypes.brain-map.org/): Cellular expression patterns in neurons and glia
• [BrainSpan - HSPA8 Developmental Expression](https://brainspan.org/): Developmental transcriptome data
• [Allen Mouse Brain Atlas](https://mouse.brain-map.org/): Mouse brain expression data

References

See Also

• [HSPA- Heat Shock Proteins](/content/proteins)
• [Hsp7- P- Autophagy Pathway](/mechanisms/autophagy-lysosome-pathway)
• [M- A- Parkinson's Disease](/proteins/parkin)
• [ALS](/diseases/amyotrophic-lateral-sclerosis)

External Links

• [UniProt: HSPA8](https://www.ncbi.nlm.nih.gov/gene/3312)
• [PDB: HSPA8 Structure](https://www.rcsb.org/structure/3H5J)
• [Human Protein Atlas: HSPA8](https://www.proteinatlas.org/gene/ENSG00000113071-HSPA8)