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 1958667674  80 GVPAEGRNPPPFPGEPWKVCVNVHSFKPEELMVKTKDGYVEVSGKHEEKQQEGGIVSKNFTKKIQL 145
Cdd:cd06480     1 GGPPEPRNPPPNSSEPWKVCVNVHSFKPEELTVKTKDGFVEVSGKHEEQQKEGGIVSKNFTKKIQL 66

Alpha-crystallin domain (ACD) found in mammalian 21.6 KDa small heat shock protein (sHsp) HspB8, also denoted as Hsp22 in humans, 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. A chaperone complex formed of HspB8 and Bag3 stimulates degradation of protein complexes by macroautophagy. HspB8 also forms complexes with Hsp27 (HspB1), MKBP (HspB2), HspB3, alphaB-crystallin (HspB5), Hsp20 (HspB6), and cvHsp (HspB7). These latter interactions may depend on phosphorylation of the respective partner sHsp. HspB8 may participate in the regulation of cell proliferation, cardiac hypertrophy, apoptosis, and carcinogenesis. Point mutations in HspB8 have been correlated with the development of several congenital neurological diseases, including Charcot Marie tooth disease and distal motor neuropathy type II.

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gi 1958667674  80 GVPAEGRNPPPFPGEPWKVCVNVHSFKPEELMVKTKDGYVEVSGKHEEKQQEGGIVSKNFTKKIQL 145
Cdd:cd06480     1 GGPPEPRNPPPNSSEPWKVCVNVHSFKPEELTVKTKDGFVEVSGKHEEQQKEGGIVSKNFTKKIQL 66

Alpha-crystallin domain (ACD) found in mammalian 21.6 KDa small heat shock protein (sHsp) HspB8, also denoted as Hsp22 in humans, 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. A chaperone complex formed of HspB8 and Bag3 stimulates degradation of protein complexes by macroautophagy. HspB8 also forms complexes with Hsp27 (HspB1), MKBP (HspB2), HspB3, alphaB-crystallin (HspB5), Hsp20 (HspB6), and cvHsp (HspB7). These latter interactions may depend on phosphorylation of the respective partner sHsp. HspB8 may participate in the regulation of cell proliferation, cardiac hypertrophy, apoptosis, and carcinogenesis. Point mutations in HspB8 have been correlated with the development of several congenital neurological diseases, including Charcot Marie tooth disease and distal motor neuropathy type II.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 1958667674  80 GVPAEGRNPPPFPGEPWKVCVNVHSFKPEELMVKTKDGYVEVSGKHEEKQQEGGIVSKNFTKKIQL 145
Cdd:cd06480     1 GGPPEPRNPPPNSSEPWKVCVNVHSFKPEELTVKTKDGFVEVSGKHEEQQKEGGIVSKNFTKKIQL 66

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 1958667674  96 WKVCVNVHSFKPEELMVKTKDGYVEVSGKHEEKQQEGGIVSKNFTKKIQL 145
Cdd:cd06475    12 WKVSLDVNHFAPEELVVKTKDGVVEITGKHEEKQDEHGFVSRCFTRKYTL 61

Alpha-crystallin domain found in the small heat shock protein (sHsp) alphaB-crystallin (HspB5, 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. HspB4 does not belong to this group. HspB5 shows increased synthesis in response to stress. HspB5 is also expressed constitutively in other tissues including brain, heart, and type I and type IIa skeletal muscle fibers, and in several cancers including gliomas, renal cell carcinomas, basal-like and metaplastic breast carcinomas, and head and neck cancer. Its functions include effects on the apoptotic pathway and on metastasis. Phosphorylation of HspB5 reduces its oligomerization and anti-apoptotic activities. HspB5 is protective in demyelinating disease such as multiple sclerosis (MS), being a negative regulator of inflammation. In early active MS lesions it is the most abundant gene transcript and an autoantigen, the immune response against it would disrupt its function and worsen inflammation and demyelination. Given as therapy for ongoing demyelinating disease it may counteract this effect. It is an autoantigen in the pathogenesis of various other inflammatory disorders including Lens-associated uveitis (LAU), and Behcet's disease. Mutations in HspB5 have been associated with diseases including dominant cataract and desmin-related myopathy.

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gi 1958667674  96 WKVCVNVHSFKPEELMVKTKDGYVEVSGKHEEKQQEGGIVSKNFTKKIQL 145
Cdd:cd06498     9 FSVNLDVKHFSPEELKVKVLGDFIEIHGKHEERQDEHGFISREFQRKYRI 58

Hsp20/alpha crystallin family; Not only do small heat-shock-proteins occur in eukaryotes and prokaryotes but they have also now been shown to occur in cyanobacterial phages as well as their bacterial hosts.

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gi 1958667674  96 WKVCVNVHSFKPEELMVKTKDGYVEVSGKHEEKQQEG-----GIVSKNFTKKIQL 145
Cdd:pfam00011   9 FEVRLDVPGFKPEELKVKVEDNRLLVKGEHEEEKEDDhglrsERSYGSFSRKFTL 63

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 1958667674  96 WKVCVNVHSFKPEELMVKTKDGYVEVSGKHEEKqQEGGIVSKNFTKKIQL 145
Cdd:cd00298     8 VVVTVDLPGVKKEDIKVEVEDNVLTISGKREEE-EERERSYGEFERSFEL 56

Alpha crystallin domain (ACD) found in mammalian HspB3, also known as heat-shock protein 27-like protein (HSPL27, 17-kDa) 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. HspB3 is expressed in adult skeletal muscle, smooth muscle, and heart, and in several other fetal tissues. In muscle cells HspB3 forms an oligomeric 150 kDa complex with myotonic dystrophy protein kinase-binding protein (MKBP/ HspB2), this complex may comprise one of two independent muscle-cell specific chaperone systems. The expression of HspB3 is induced during muscle differentiation controlled by the myogenic factor MyoD. HspB3 may also interact with Hsp22 (HspB8).

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gi 1958667674  89 PPFPGEP-WKVCVNVHSFKPEELMVKTKDGYVEVSGKHEEKQQEGGIVSKNFTKKIQLRN 147
Cdd:cd06477     1 DQEEGKPmFQILLDVVQFRPEDIIIQVFEGWLLIKGQHGVRMDEHGFISRSFTRQYQLPD 60

Alpha-crystallin domain (ACD) found in Escherichia coli inclusion body-associated proteins IbpA and IbpB, and similar proteins. IbpA and IbpB are 16 kDa small heat shock proteins (sHsps). sHsps are molecular chaperones that suppress protein aggregation and protect against cell stress, and are generally active as large oligomers consisting of multiple subunits. IbpA and IbpB are produced during high-level production of various heterologous proteins, specifically human prorenin, renin and bovine insulin-like growth factor 2 (bIGF-2), and are strongly associated with inclusion bodies containing these heterologous proteins. IbpA and IbpB work as an integrated system to stabilize thermally aggregated proteins in a disaggregation competent state. The chaperone activity of IbpB is also significantly elevated as the temperature increases from normal to heat shock. The high temperature results in the disassociation of 2-3-MDa IbpB oligomers into smaller approximately 600-kDa structures. This elevated activity seen under heat shock conditions is retained for an extended period of time after the temperature is returned to normal. IbpA also forms multimers.

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gi 1958667674 100 VNVHSFKPEELMVKTKDGYVEVSGKHEEKQQEG------GIVSKNFTKKIQL 145
Cdd:cd06470    17 LAVAGFSEDDLEIEVENNQLTVTGKKADEENEEreylhrGIAKRAFERSFNL 68

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 1958667674  98 VCVNVHSFKPEELMVKTKDGYVEVSGKHEEKQQEG 132
Cdd:cd06481    11 LKLDVRGFSPEDLSVRVDGRKLVVTGKREKKNEDE 45