alpha-crystallin B chain; alpha(B)-crystallin; heat shock protein beta-5; HspB5; renal carcinoma antigen NY-REN-27; Rosenthal fiber component (CRYAB CRYA2)

Function

• may contribute to the transparency & refractive index of the lens
• aggregates with homologous proteins, including alpha-A crystallin (CRYAA) & HSPB1 (hsp28), to form large heteromeric complexes
• interacts with HSPBAP1 & TTN/titin

Structure

• homodimer
• belongs to the small heat shock protein (HSP20) family

Compartment

• cytoplasm, nucleus
• translocates to the nucleus during heat shock
  • resides in nuclear speckles

Expression

• lens
• other tissues
• brain & Rosenthal fibers in Alexander's disease

Pathology

• mutations associated with alpha-B crystallinopathy
• antibodies to CRYAB in spinal fluid of patients with multiple sclerosis
• CRYAB confers protective effect in experimental autoimmune encephalomyelitis
• defects in CRYAB are the cause of
  • myofibrillar myopathy type 2
  • cataract posterior polar type 2
  • myofibrillar myopathy fatal infantile hypertonic

More general terms

• protein subunit
• heat shock protein [hsp]-20 family
• glycoprotein
• phosphoprotein

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=1410
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:1410
• OMIM: https://mirror.omim.org/entry/123590
• OMIM: https://mirror.omim.org/entry/608810
• OMIM: https://mirror.omim.org/entry/613763
• OMIM: https://mirror.omim.org/entry/613869
• UniProt: http://www.uniprot.org/uniprot/P02511.html