Heat Shock Protein Beta 8 (HSPb8)

CMT2L; DHMN2; E2IG1; H11; HMN2; HSP22; Heat Shock 22kDa Protein 8; Alpha-crystallin C chain; E2-induced gene 1 protein; Small stress protein-like protein HSP22

SPN	U810
HGNC	30171
MGI	2135756
PubMed	23536091
RGD	71003
UniProt	Q9UJY1
Wiki	HSPB8

In most cells, cotransfection with HSPB8 blocked inclusion formation. Biochemical analyses indicated that HSPB8 inhibited the accumulation of insoluble Htt43Q as efficiently as HSP40 (DNAJB1), which was taken as a positive control. Htt43Q then accumulated in the SDS-soluble fraction, provided that protein degradation was blocked by proteasome and autophagy inhibitors. In contrast, HSPB1 and alpha-B-crystallin (CRYAB) had no effect. Analyses of HSPB1/HSPB8 chimeric proteins indicated that the C-terminal domain of HSPB8 contains the specific sequence necessary for chaperone activity.

The K141N mutation significantly reduced the chaperone activity of the protein. Carra et al. (2005) hypothesized that a decrease in HSPB8 chaperone activity may contribute to the development of some neuropathies.

Reference

"Effects of estrogen on global gene expression: identification of novel targets of estrogen action."
Cancer Res. 60:5977-5983(2000) [PubMed] [Europe PMC] [Abstract]

"HSP22, a new member of the small heat shock protein superfamily, interacts with mimic of phosphorylated HSP27 (3DHSP27)."
J. Biol. Chem. 276:26753-26761(2001) [PubMed] [Europe PMC] [Abstract]

"A novel human gene similar to the protein kinase (PK) coding domain of the large subunit of herpes simplex virus type 2 ribonucleotide reductase (ICP10) codes for a serine-threonine PK and is expressed in melanoma cells."
J. Biol. Chem. 275:25690-25699(2000) [PubMed] [Europe PMC] [Abstract]

"Towards a catalog of human genes and proteins: sequencing and analysis of 500 novel complete protein coding human cDNAs."
Genome Res. 11:422-435(2001) [PubMed] [Europe PMC] [Abstract]

"Large-scale cDNA transfection screening for genes related to cancer development and progression."
Proc. Natl. Acad. Sci. U.S.A. 101:15724-15729(2004) [PubMed] [Europe PMC] [Abstract]

"Complete sequencing and characterization of 21,243 full-length human cDNAs."
Nat. Genet. 36:40-45(2004) [PubMed] [Europe PMC] [Abstract]

"The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC)."
Genome Res. 14:2121-2127(2004) [PubMed] [Europe PMC] [Abstract]

"Phosphopeptide derivatization signatures to identify serine and threonine phosphorylated peptides by mass spectrometry."
Anal. Chem. 73:5387-5394(2001) [PubMed] [Europe PMC] [Abstract]

"Characterization of two novel human small heat shock proteins: protein kinase-related HspB8 and testis-specific HspB9."
Biochim. Biophys. Acta 1520:1-6(2001) [PubMed] [Europe PMC] [Abstract]

"Combining protein-based IMAC, peptide-based IMAC, and MudPIT for efficient phosphoproteomic analysis."
J. Proteome Res. 7:1346-1351(2008) [PubMed] [Europe PMC] [Abstract]

"A quantitative atlas of mitotic phosphorylation."
Proc. Natl. Acad. Sci. U.S.A. 105:10762-10767(2008) [PubMed] [Europe PMC] [Abstract]

"HSPB7 is a SC35 speckle resident small heat shock protein."
Biochim. Biophys. Acta 1793:1343-1353(2009) [PubMed] [Europe PMC] [Abstract]

"Initial characterization of the human central proteome."
BMC Syst. Biol. 5:17-17(2011) [PubMed] [Europe PMC] [Abstract]

"Mutations affecting the cytoplasmic functions of the co-chaperone DNAJB6 cause limb-girdle muscular dystrophy."
Nat. Genet. 44:450-455(2012) [PubMed] [Europe PMC] [Abstract]

"Hot-spot residue in small heat-shock protein 22 causes distal motor neuropathy."
Nat. Genet. 36:597-601(2004) [PubMed] [Europe PMC] [Abstract]

"Small heat-shock protein 22 mutated in autosomal dominant Charcot-Marie-Tooth disease type 2L."
Hum. Genet. 116:222-224(2005) [PubMed] [Europe PMC] [Abstract]

"Patterns of somatic mutation in human cancer genomes."
Nature 446:153-158(2007) [PubMed] [Europe PMC] [Abstract]