STUB1 also known as CHIP (C terminus of HSC70-Interacting Protein), is a human 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 CHIP protein encoded by this gene binds to and inhibits the 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...

 activity of the chaperone proteins HSC70 and 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...

 and blocks the forward reaction of the HSC70-HSP70 substrate-binding cycle. In addition, CHIP possesses E3 ubiquitin ligase

Ubiquitin ligase

A ubiquitin ligase is a protein that in combination with an E2 ubiquitin-conjugating enzyme causes the attachment of ubiquitin to a lysine on a target protein via an isopeptide bond; the E3 ubiquitin ligase targets specific protein substrates for degradation by the proteasome...

 activity and promotes ubiquitylation. CHIP enhances HSP70 induction during acute stress and also mediates its turnover during the stress recovery process. Hence CHIP appears to maintain protein homeostasis by controlling chaperone levels during stress and recovery.

Interactions

STUB1 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 C-Raf

C-Raf

RAF proto-oncogene serine/threonine-protein kinase also known as proto-oncogene c-RAF or simply c-Raf is an enzyme that in humans is encoded by the RAF1 gene. The c-Raf protein functions in the MAPK/ERK signal transduction pathway as part of a protein kinase cascade...

, 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...

, DNAJB1

DNAJB1

DnaJ homolog subfamily B member 1 is a protein that in humans is encoded by the DNAJB1 gene.-Interactions:DNAJB1 has been shown to interact with STUB1 and HSPA4.-Further reading:...

, HSPA8, RUNX2

Runx2

Runt-related transcription factor 2 also known as core-binding factor subunit alpha-1 is a protein that in humans is encoded by the RUNX2 gene RUNX2 is a key transcription factor associated with osteoblast differentiation....

, HSPA1A

HSPA1A

Heat shock 70 kDa protein 1 is a protein that in humans is encoded by the HSPA1A gene.-Interactions:HSPA1A has been shown to interact with ASK1, STUB1, MSR1, BAG3, Parkin , Fanconi anemia, complementation group C, GPR37, HSF1 and AIFM1....

 and HSPA4

HSPA4

Heat shock 70 kDa protein 4 is a protein that in humans is encoded by the HSPA4 gene.The protein encoded by this gene was originally suggested to be a member of the heat shock protein 70 family...

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Further reading