UniProt functional annotation for P02470



	UniProt functional annotation for P02470

UniProt code: P02470.

Organism: Bos taurus (Bovine).

Taxonomy: Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Laurasiatheria; Artiodactyla; Ruminantia; Pecora; Bovidae; Bovinae; Bos.

Function: Contributes to the transparency and refractive index of the lens (By similarity). Acts as a chaperone, preventing aggregation of various proteins under a wide range of stress conditions (PubMed:20440841). Required for the correct formation of lens intermediate filaments as part of a complex composed of BFSP1, BFSP2 and CRYAA (By similarity). {ECO:0000250|UniProtKB:P02489, ECO:0000269|PubMed:20440841}.

Subunit: Heteromer composed of three CRYAA and one CRYAB subunits (By similarity). Inter-subunit bridging via zinc ions enhances stability, which is crucial as there is no protein turn over in the lens (By similarity) (PubMed:20440841). Can also form homodimers and homotetramers (dimers of dimers) which serve as the building blocks of homooligomers. Within homooligomers, the zinc-binding motif is created from residues of 3 different molecules. His-100 and Glu-102 from one molecule are ligands of the zinc ion, and His-107 and His-154 residues from additional molecules complete the site with tetrahedral coordination geometry (PubMed:20440841). Part of a complex required for lens intermediate filament formation composed of BFSP1, BFSP2 and CRYAA (By similarity). {ECO:0000250|UniProtKB:P02489, ECO:0000269|PubMed:20440841}.

Subcellular location: Cytoplasm {ECO:0000250|UniProtKB:P02489}. Nucleus {ECO:0000250|UniProtKB:P02489}. Note=Translocates to the nucleus during heat shock and resides in sub-nuclear structures known as SC35 speckles or nuclear splicing speckles. {ECO:0000250|UniProtKB:P02489}.

Ptm: Acetylation at Lys-70 may increase chaperone activity. {ECO:0000250|UniProtKB:P02489}.

Ptm: Undergoes age-dependent proteolytical cleavage at the C-terminus. {ECO:0000269|PubMed:8529423}.

Similarity: Belongs to the small heat shock protein (HSP20) family. {ECO:0000255|PROSITE-ProRule:PRU00285}.

Annotations taken from UniProtKB at the EBI.


Organism:		Bos taurus (Bovine).
Taxonomy:		Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Laurasiatheria; Artiodactyla; Ruminantia; Pecora; Bovidae; Bovinae; Bos.



Function:		Contributes to the transparency and refractive index of the lens (By similarity). Acts as a chaperone, preventing aggregation of various proteins under a wide range of stress conditions (PubMed:20440841). Required for the correct formation of lens intermediate filaments as part of a complex composed of BFSP1, BFSP2 and CRYAA (By similarity). {ECO:0000250\|UniProtKB:P02489, ECO:0000269\|PubMed:20440841}.


Subunit:		Heteromer composed of three CRYAA and one CRYAB subunits (By similarity). Inter-subunit bridging via zinc ions enhances stability, which is crucial as there is no protein turn over in the lens (By similarity) (PubMed:20440841). Can also form homodimers and homotetramers (dimers of dimers) which serve as the building blocks of homooligomers. Within homooligomers, the zinc-binding motif is created from residues of 3 different molecules. His-100 and Glu-102 from one molecule are ligands of the zinc ion, and His-107 and His-154 residues from additional molecules complete the site with tetrahedral coordination geometry (PubMed:20440841). Part of a complex required for lens intermediate filament formation composed of BFSP1, BFSP2 and CRYAA (By similarity). {ECO:0000250\|UniProtKB:P02489, ECO:0000269\|PubMed:20440841}.
Subcellular location:		Cytoplasm {ECO:0000250\|UniProtKB:P02489}. Nucleus {ECO:0000250\|UniProtKB:P02489}. Note=Translocates to the nucleus during heat shock and resides in sub-nuclear structures known as SC35 speckles or nuclear splicing speckles. {ECO:0000250\|UniProtKB:P02489}.
Ptm:		Acetylation at Lys-70 may increase chaperone activity. {ECO:0000250\|UniProtKB:P02489}.
Ptm:		Undergoes age-dependent proteolytical cleavage at the C-terminus. {ECO:0000269\|PubMed:8529423}.
Similarity:		Belongs to the small heat shock protein (HSP20) family. {ECO:0000255\|PROSITE-ProRule:PRU00285}.