alpha-crystallin domain (ACD) found in alpha-crystallin-type small heat shock proteins, and a similar domain found in p23 (a cochaperone for Hsp90) and in other p23-like proteins.; The alpha-crystallin-Hsps_p23-like superfamily includes the alpha-crystallin domain (ACD) of alpha-crystallin-type small heat shock proteins (sHsps) and a similar domain found in p23-like proteins. sHsps are small stress induced proteins with monomeric masses between 12-43 kDa, whose common feature is this ACD. sHsps are generally active as large oligomers consisting of multiple subunits, and are believed to be ATP-independent chaperones that prevent aggregation and are important in refolding in combination with other Hsps. p23 is a cochaperone of the Hsp90 chaperoning pathway. It binds Hsp90 and participates in the folding of a number of Hsp90 clients including the progesterone receptor. p23 also has a passive chaperoning activity. p23 in addition may act as the cytosolic prostaglandin E2 synthase. Included in this superfamily is the p23-like C-terminal CHORD-SGT1 (CS) domain of suppressor of G2 allele of Skp1 (Sgt1) and the p23-like domains of human butyrate-induced transcript 1 (hB-ind1), NUD (nuclear distribution) C, Melusin, and NAD(P)H cytochrome b5 (NCB5) oxidoreductase (OR).

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                 ....*....|....*....|....*....|....*....|..
gi 759177935 105 QDDHGYISREFHRRYRLPSNVDQSALSCSLSADGMLTFSGPK 146
Cdd:cd06497   45 QDDHGYISREFHRRYRLPSNVDQSAITCSLSADGMLTFSGPK 86

Alpha-crystallin domain found in the small heat shock protein (sHsp) alphaA-crystallin (HspB4, 20kDa). sHsps are molecular chaperones that suppress protein aggregation and protect against cell stress, and are generally active as large oligomers consisting of multiple subunits. Alpha crystallin, an abundant protein in the mammalian lens, is a large (700 kDa) heteropolymer composed of HspB4 and HspB5, generally in a molar ratio of HspB4:HspB5 of 3:1. Only trace amounts of HspB4 are found in tissues other than the lens. HspB5 does not belong to this group. Mutations inHspB4 have been associated with Autosomal Dominant Congenital Cataract (ADCC). The chaperone-like functions of HspB4 are considered important for maintaining lens transparency and preventing cataract.

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                 ....*....|....*....|....*....|....*....|..
gi 759177935 105 QDDHGYISREFHRRYRLPSNVDQSALSCSLSADGMLTFSGPK 146
Cdd:cd06497   45 QDDHGYISREFHRRYRLPSNVDQSAITCSLSADGMLTFSGPK 86

Small heat shock protein IbpA, HSP20 family [Posttranslational modification, protein turnover, chaperones];

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                 ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 759177935 104 PQDDHGYISRE-----FHRRYRLPSNVDQSALSCSLSaDGMLTFSGPKVPSGVdaghsERAIPVSRE 165
Cdd:COG0071   45 EEEGENYLRRErrygsFERSFTLPDDVDVDKIEASYE-NGVLTITLPKAEEAK-----PRKIEIKAG 105

Alpha-crystallin domain found in the small heat shock protein (sHsp) alphaA-crystallin (HspB4, 20kDa). sHsps are molecular chaperones that suppress protein aggregation and protect against cell stress, and are generally active as large oligomers consisting of multiple subunits. Alpha crystallin, an abundant protein in the mammalian lens, is a large (700 kDa) heteropolymer composed of HspB4 and HspB5, generally in a molar ratio of HspB4:HspB5 of 3:1. Only trace amounts of HspB4 are found in tissues other than the lens. HspB5 does not belong to this group. Mutations inHspB4 have been associated with Autosomal Dominant Congenital Cataract (ADCC). The chaperone-like functions of HspB4 are considered important for maintaining lens transparency and preventing cataract.

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                 ....*....|....*....|....*....|....*....|..
gi 759177935 105 QDDHGYISREFHRRYRLPSNVDQSALSCSLSADGMLTFSGPK 146
Cdd:cd06497   45 QDDHGYISREFHRRYRLPSNVDQSAITCSLSADGMLTFSGPK 86

Alpha-crystallin domain (ACD) of metazoan alpha-crystallin-type small(s) heat shock proteins (Hsps). sHsps are small stress induced proteins with monomeric masses between 12 -43 kDa, whose common feature is the Alpha-crystallin domain (ACD). sHsps are generally active as large oligomers consisting of multiple subunits, and are believed to be ATP-independent chaperones that prevent aggregation and are important in refolding in combination with other Hsps.

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                 ....*....|....*....|....*....|....*....|..
gi 759177935 105 QDDHGYISREFHRRYRLPSNVDQSALSCSLSADGMLTFSGPK 146
Cdd:cd06526   42 EDEHGYVSREFTRRYQLPEGVDPDSVTSSLSSDGVLTIEAPK 83

Alpha crystallin domain (ACD) found in mammalian small (s)heat shock protein (Hsp)-27 (also denoted HspB1 in human) and similar proteins. sHsps are molecular chaperones that suppress protein aggregation and protect against cell stress, and are generally active as large oligomers consisting of multiple subunits. Hsp27 shows enhanced synthesis in response to stress. It is a molecular chaperone which interacts with a large number of different proteins. It is found in many types of human cells including breast, uterus, cervix, platelets and cancer cells. Hsp27 has diverse cellular functions including, chaperoning, regulation of actin polymerization, keratinocyte differentiation, regulation of inflammatory pathways in keratinocytes, and protection from oxidative stress through modulating glutathione levels. It is also a subunit of AUF1-containing protein complexes. It has been linked to several transduction pathways regulating cellular functions including differentiation, cell growth, development, and apoptosis. Its activity can be regulated by phosphorylation. Its unphosphorylated state is a high molecular weight aggregated form (100-800kDa) composed of up to 24 subunits, which forms as a result of multiple interactions within the ACD, and is required for chaperone function and resistance to oxidative stress. Upon phosphorylation these large aggregates rapidly disassociate to smaller oligomers and chaperone activity is modified. High constitutive levels of Hsp27 have been detected in various cancer cells, in particular those of carcinoma origin. Over-expression of Hsp27 has a protective effect against various diseases-processes, including Huntington's disease. Mutations in Hsp27 have been associated with a form of distal hereditary motor neuropathy type II and Charcot-Marie-Tooth disease type 2.

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gi 759177935 105 QDDHGYISREFHRRYRLPSNVDQSALSCSLSADGMLTFSGP 145
Cdd:cd06475   45 QDEHGFVSRCFTRKYTLPPGVDPTAVTSSLSPDGILTVEAP 85

Alpha crystallin domain (ACD) found in mammalian small heat shock protein (sHsp) HspB2/heat shock 27kDa protein 2 and similar proteins. sHsps are molecular chaperones that suppress protein aggregation and protect against cell stress, and are generally active as large oligomers consisting of multiple subunits. HspB2 is preferentially and constitutively expressed in skeletal muscle and heart. HspB2 shows homooligomeric activity and forms aggregates in muscle cytosol. Although its expression is not induced by heat shock, it redistributes to the insoluble fraction in response to heat shock. In the mouse heart, HspB2 plays a role in maintaining energetic balance, by protecting cardiac energetics during ischemia/reperfusion, and allowing for increased work during acute inotropic challenge. hHspB2 [previously also known as myotonic dystrophy protein kinase (DMPK) binding protein (MKBP)] is selectively up-regulated in skeletal muscles from myotonic dystrophy patients. The ACD of hHspB2 binds the DMPK kinase domain. In vitro, hHspB2 enhances the kinase activity of DMPK and confers thermoresistance. The hHspB2 gene lies less than 1kb from the 5 prime end of the related alphaB (HspB4)-crystallin gene, with the opposite transcription direction. These two genes may share regulatory elements for their expression.

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gi 759177935 104 PQ--DDHGYISREFHRRYRLPSNVDQSALSCSLSADGMLTFSGPK 146
Cdd:cd06476   39 PQrmDRHGFVSREFTRTYILPMDVDPLLVRASLSHDGILCIQAPR 83

This domain family includes the alpha-crystallin domain (ACD) of alpha-crystallin-type small heat shock proteins (sHsps) and a similar domain found in p23-like proteins. sHsps are small stress induced proteins with monomeric masses between 12 -43 kDa, whose common feature is this ACD. sHsps are generally active as large oligomers consisting of multiple subunits, and are believed to be ATP-independent chaperones that prevent aggregation and are important in refolding in combination with other Hsps. p23 is a cochaperone of the Hsp90 chaperoning pathway. It binds Hsp90 and participates in the folding of a number of Hsp90 clients including the progesterone receptor. p23 also has a passive chaperoning activity. p23 in addition may act as the cytosolic prostaglandin E2 synthase. Included in this family is the p23-like C-terminal CHORD-SGT1 (CS) domain of suppressor of G2 allele of Skp1 (Sgt1) and the p23-like domains of human butyrate-induced transcript 1 (hB-ind1), NUD (nuclear distribution) C, Melusin, and NAD(P)H cytochrome b5 (NCB5) oxidoreductase (OR).

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                 ....*....|....*....|....*....|....*....|....*...
gi 759177935  99 RARGWPQDDHGYISREFHRRYRLPSNVDQSALSCSLSaDGMLTFSGPK 146
Cdd:cd00298   34 SGKREEEEERERSYGEFERSFELPEDVDPEKSKASLE-NGVLEITLPK 80

Alpha crystallin domain (ACD) found in mammalian small heat shock protein (sHsp) HspB9 and similar proteins. sHsps are molecular chaperones that suppress protein aggregation and protect against cell stress, and are generally active as large oligomers consisting of multiple subunits. Human (h) HspB9 is expressed exclusively in the normal testis and in various tumor samples and is a cancer/testis antigen. hHspB9 interacts with TCTEL1 (T-complex testis expressed protein -1), a subunit of dynein. hHspB9 and TCTEL1 are co-expressed in similar cells within the testis and in tumor cells. Included in this group is Xenopus Hsp30, a developmentally-regulated heat-inducible molecular chaperone.

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gi 759177935 110 YISREFHRRYRLPSNVDQSALSCSLSADGMLTFSGP 145
Cdd:cd06481   51 YEYQEFVREAQLPEHVDPEAVTCSLSPSGHLHIRAP 86