CRYAB_SPAJD
ID CRYAB_SPAJD Reviewed; 175 AA.
AC Q9EPF3;
DT 26-APR-2004, integrated into UniProtKB/Swiss-Prot.
DT 01-MAR-2001, sequence version 1.
DT 03-AUG-2022, entry version 76.
DE RecName: Full=Alpha-crystallin B chain;
DE AltName: Full=Alpha(B)-crystallin;
GN Name=CRYAB;
OS Spalax judaei (Judean Mountains blind mole rat) (Nannospalax judaei).
OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia;
OC Eutheria; Euarchontoglires; Glires; Rodentia; Myomorpha; Muroidea;
OC Spalacidae; Spalacinae; Nannospalax.
OX NCBI_TaxID=134510;
RN [1]
RP NUCLEOTIDE SEQUENCE [MRNA].
RC STRAIN=Isolate Anza population; TISSUE=Heart, and Lens;
RX PubMed=11245977; DOI=10.1016/s0378-1119(00)00603-x;
RA Avivi A., Joel A., Nevo E.;
RT "The lens protein alpha-B-crystallin of the blind subterranean mole-rat:
RT high homology with sighted mammals.";
RL Gene 264:45-49(2001).
CC -!- FUNCTION: May contribute to the transparency and refractive index of
CC the lens. Has chaperone-like activity, preventing aggregation of
CC various proteins under a wide range of stress conditions. In lens
CC epithelial cells, stabilizes the ATP6V1A protein, preventing its
CC degradation by the proteasome (By similarity).
CC {ECO:0000250|UniProtKB:P23927}.
CC -!- SUBUNIT: Heteromer composed of three CRYAA and one CRYAB subunits.
CC Aggregates with homologous proteins, including the small heat shock
CC protein HSPB1, to form large heteromeric complexes. Inter-subunit
CC bridging via zinc ions enhances stability, which is crucial as there is
CC no protein turn over in the lens. Interacts with HSPBAP1 and TTN/titin.
CC Interacts with TMEM109. Interacts with DES; binds rapidly during early
CC stages of DES filament assembly and a reduced binding seen in the later
CC stages. Interacts with ATP6V1A and with MTOR, forming a ternary complex
CC (By similarity). {ECO:0000250|UniProtKB:P02511,
CC ECO:0000250|UniProtKB:P23927}.
CC -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000250|UniProtKB:P02511}. Nucleus
CC {ECO:0000250|UniProtKB:P02511}. Secreted
CC {ECO:0000250|UniProtKB:P02511}. Lysosome
CC {ECO:0000250|UniProtKB:P23927}. Note=Translocates to the nucleus during
CC heat shock and resides in sub-nuclear structures known as SC35 speckles
CC or nuclear splicing speckles. Localizes at the Z-bands and the
CC intercalated disk in cardiomyocytes. {ECO:0000250|UniProtKB:P02511}.
CC -!- TISSUE SPECIFICITY: Lens as well as other tissues.
CC -!- SIMILARITY: Belongs to the small heat shock protein (HSP20) family.
CC {ECO:0000255|PROSITE-ProRule:PRU00285}.
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DR EMBL; AJ293658; CAC01692.1; -; mRNA.
DR AlphaFoldDB; Q9EPF3; -.
DR SMR; Q9EPF3; -.
DR GO; GO:0005737; C:cytoplasm; ISS:UniProtKB.
DR GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR GO; GO:0005764; C:lysosome; IEA:UniProtKB-SubCell.
DR GO; GO:0005634; C:nucleus; ISS:UniProtKB.
DR GO; GO:0032991; C:protein-containing complex; ISS:UniProtKB.
DR GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR GO; GO:0042803; F:protein homodimerization activity; ISS:UniProtKB.
DR GO; GO:0005212; F:structural constituent of eye lens; IEA:UniProtKB-KW.
DR GO; GO:0045892; P:negative regulation of transcription, DNA-templated; ISS:UniProtKB.
DR Gene3D; 2.60.40.790; -; 1.
DR InterPro; IPR002068; A-crystallin/Hsp20_dom.
DR InterPro; IPR001436; Alpha-crystallin/sHSP_animal.
DR InterPro; IPR003090; Alpha-crystallin_N.
DR InterPro; IPR008978; HSP20-like_chaperone.
DR PANTHER; PTHR45640; PTHR45640; 1.
DR Pfam; PF00525; Crystallin; 1.
DR Pfam; PF00011; HSP20; 1.
DR PIRSF; PIRSF036514; Sm_HSP_B1; 1.
DR PRINTS; PR00299; ACRYSTALLIN.
DR SUPFAM; SSF49764; SSF49764; 1.
DR PROSITE; PS01031; SHSP; 1.
PE 2: Evidence at transcript level;
KW Acetylation; Chaperone; Cytoplasm; Eye lens protein; Glycoprotein;
KW Lysosome; Metal-binding; Methylation; Nucleus; Phosphoprotein; Secreted;
KW Zinc.
FT CHAIN 1..175
FT /note="Alpha-crystallin B chain"
FT /id="PRO_0000125915"
FT DOMAIN 56..164
FT /note="sHSP"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00285"
FT REGION 142..175
FT /note="Disordered"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT COMPBIAS 159..175
FT /note="Basic and acidic residues"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT BINDING 83
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /ligand_label="1"
FT /evidence="ECO:0000250"
FT BINDING 104
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /ligand_label="2"
FT /evidence="ECO:0000250"
FT BINDING 106
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /ligand_label="2"
FT /evidence="ECO:0000250"
FT BINDING 111
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /ligand_label="1"
FT /evidence="ECO:0000250"
FT BINDING 119
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /ligand_label="1"
FT /evidence="ECO:0000250"
FT MOD_RES 1
FT /note="N-acetylmethionine"
FT /evidence="ECO:0000250|UniProtKB:P02510"
FT MOD_RES 19
FT /note="Phosphoserine"
FT /evidence="ECO:0000250|UniProtKB:P02510"
FT MOD_RES 45
FT /note="Phosphoserine"
FT /evidence="ECO:0000250|UniProtKB:P02510"
FT MOD_RES 59
FT /note="Phosphoserine"
FT /evidence="ECO:0000250|UniProtKB:P02510"
FT MOD_RES 92
FT /note="N6-acetyllysine"
FT /evidence="ECO:0000250|UniProtKB:P02511"
FT MOD_RES 166
FT /note="N6-acetyllysine"
FT /evidence="ECO:0000250|UniProtKB:P02511"
FT CARBOHYD 170
FT /note="O-linked (GlcNAc) threonine"
FT /evidence="ECO:0000250"
SQ SEQUENCE 175 AA; 20105 MW; 3BD653E0898B612F CRC64;
MDIAIHHPWI RRPFFPFHSP SRLFDQFFGE HLLESDLFST STSLSPFYLR PPSFFRAPSW
IDTGLSEMRM EKDRLSVNLD VKHFSPEELK VKVLGDVIEV HGKHEERQDE HGFISREFHR
KYRIPADVDP LTITSSLSSD GVLTVNGPRK QASGPERTIP ITREEKPAVT AAPKK