beta-2-microglobulin (B2M)

Function

• beta-chain (light chain) of MHC class 1 molecules

Structure

• belongs to the beta-2-microglobulin family
• contains 1 Ig-like C1-type domain (immunoglobulin-like)

Compartment

secreted

Expression

• synthesized by all nucleated cell types

Pathology

• age-associated increase in plasma levels in humans & mice
  • higher levels accumulate in plasma of patients with ESRD
• glycation of Ile-21 is observed in long-term hemodialysis patients
• may be deposited in tissues in some types of amyloidosis
• defects in B2M are the cause of hypercatabolic hypoproteinemia

Comparative biology

• B2M negatively regulates older age-associated cognitive regenerative function in hippocampus of mice
• exogenous B2M injected systemically impairs hippocampal- dependent cognitive function & neurogenesis in young mice

More general terms

• protein subunit
• microglobulin
• beta 2 globulin

Additional terms

• amyloidosis
• beta-2 microglobulin in body fluid

Component of

• MHC class I antigen

Database

• UniProt: http://www.uniprot.org/uniprot/P61769.html
• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=567
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:567
• OMIM: https://mirror.omim.org/entry/109700
• OMIM: https://mirror.omim.org/entry/241600