Heat shock 70 kDa protein 8 also known as heat shock cognate 71 kDa protein or Hsc70 or Hsp73 is a heat shock protein

Heat shock protein

Heat shock proteins are a class of functionally related proteins involved in the folding and unfolding of other proteins. Their expression is increased when cells are exposed to elevated temperatures or other stress. This increase in expression is transcriptionally regulated...

 that in humans is encoded by the HSPA8 gene

Gene

A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...

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Function

The heat shock protein 70 (Hsp70

Hsp70

The 70 kilodalton heat shock proteins are a family of ubiquitously expressed heat shock proteins. Proteins with similar structure exist in virtually all living organisms...

) family contains both heat-inducible and constitutively expressed members. The latter are called heat-shock cognate (Hsc) proteins. The heat shock 70 kDa protein 8 also known as Hsc70 belongs to the heat-shock cognate subgroup. This protein binds to nascent polypeptides to facilitate correct protein folding

Protein folding

Protein folding is the process by which a protein structure assumes its functional shape or conformation. It is the physical process by which a polypeptide folds into its characteristic and functional three-dimensional structure from random coil....

. It also functions as an ATPase

ATPase

ATPases are a class of enzymes that catalyze the decomposition of adenosine triphosphate into adenosine diphosphate and a free phosphate ion. This dephosphorylation reaction releases energy, which the enzyme harnesses to drive other chemical reactions that would not otherwise occur...

 in the disassembly of clathrin

Clathrin

Clathrin is a protein that plays a major role in the formation of coated vesicles. Clathrin was first isolated and named by Barbara Pearse in 1975. It forms a triskelion shape composed of three clathrin heavy chains and three light chains. When the triskelia interact they form a polyhedral lattice...

-coated vesicles during transport of membrane components through the cell. Two alternatively spliced variants have been characterized to date.

HSPA8 is ATPase

ATPase

ATPases are a class of enzymes that catalyze the decomposition of adenosine triphosphate into adenosine diphosphate and a free phosphate ion. This dephosphorylation reaction releases energy, which the enzyme harnesses to drive other chemical reactions that would not otherwise occur...

 that works with auxilin

DNAJC6

Putative tyrosine-protein phosphatase auxilin is an enzyme that in humans is encoded by the DNAJC6 gene.-Further reading:...

 to remove clathrin

Clathrin

Clathrin is a protein that plays a major role in the formation of coated vesicles. Clathrin was first isolated and named by Barbara Pearse in 1975. It forms a triskelion shape composed of three clathrin heavy chains and three light chains. When the triskelia interact they form a polyhedral lattice...

 coated vesicles. In neurons, synaptojanin

Synaptojanin

Synaptojanin is a protein involved in vesicle uncoating in neurons. This is an important regulatory lipid phosphatase. It dephosphorylates the D-5 position phosphate from Phosphatidylinositol -trisphosphate and Phosphatidylinositol -bisphosphate. It belongs to family of 5-phosphatases, which are...

 is also an important protein involved in vesicle uncoating.

Hsc70 vs Hsp70 comparison

Human Hsc70 has 85% identity with human Hsp70 (SDSC workbench, blosom26 default analysis). The scientific community has long assumed that Hsp70 and Hsc70 have similar cellular roles, but this assumption proved erroneous.

Unlike canonical heat shock proteins, Hsc70 is constitutively expressed and performs functions related to normal cellular processes. Hsc70 was placed in the heat shock protein family due to homology with other heat shock proteins.

Interactions

HSPA8 has been shown to interact

Protein-protein interaction

Protein–protein interactions occur when two or more proteins bind together, often to carry out their biological function. Many of the most important molecular processes in the cell such as DNA replication are carried out by large molecular machines that are built from a large number of protein...

 with STUB1

STUB1

STUB1 , also known as CHIP , is a human gene.- Function :...

, BAG3

BAG3

BAG family molecular chaperone regulator 3 is a protein that in humans is encoded by the BAG3 gene.BAG gene has been implicated in age related neurodegenerative diseases as Alzheimer's. It has been demonstrated that BAG1 and BAG 3 regulate the proteasomal and lysosomal protein elimination...

, BAG4

BAG4

BAG family molecular chaperone regulator 4 is a protein that in humans is encoded by the BAG4 gene.-Interactions:BAG4 has been shown to interact with HSPA8, TNFRSF1A and APOBEC1.-Further reading:...

, Parkin (ligase)

Parkin (ligase)

Parkin is a protein which in humans is encoded by the PARK2 gene. The precise function of this protein is unknown; however, the protein is a component of a multiprotein E3 ubiquitin ligase complex which in turn is part of the ubiquitin-proteasome system that mediates the targeting of proteins for...

, BAG2

BAG2

BAG family molecular chaperone regulator 2 is a protein that in humans is encoded by the BAG2 gene.-Further reading:...

, HSPBP1

HSPBP1

Hsp70-binding protein 1 is a protein that in humans is encoded by the HSPBP1 gene.-Interactions:HSPBP1 has been shown to interact with HSPA8 and HSPA4.-Further reading:...

, CDC5L

CDC5L

Cell division cycle 5-like protein is a protein that in humans is encoded by the CDC5L gene.-Interactions:CDC5L has been shown to interact with SRRM1, RPS25, SF3B1, ILF2, CWC15, DNA-PKcs, GCN1L1, BZW1, TTF2, SF3B2, SFRS2, ASF/SF2, PLRG1, DYNC1H1, PPP1CA, Small nuclear ribonucleoprotein D1, SF3B4,...

, BAG1

BAG1

BAG family molecular chaperone regulator 1 is a protein that in humans is encoded by the BAG1 gene.BAG gene has been implicated in age related neurodegenerative diseases as Alzheimer's...

, DNAJA3

DNAJA3

DnaJ homolog subfamily A member 3, mitochondrial is a protein that in humans is encoded by the DNAJA3 gene.-Interactions:DNAJA3 has been shown to interact with HSPA8, RAS p21 protein activator 1 and Janus kinase 2.-Further reading:...

 and CITED1

CITED1

Cbp/p300-interacting transactivator 1 is a protein that in humans is encoded by the CITED1 gene.-Interactions:CITED1 has been shown to interact with HSPA8 and EP300.-Further reading:...

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