Bcl-G, a novel pro-apoptotic member of the Bcl-2 family

J Biol Chem. 2001 Jan 26;276(4):2780-5. doi: 10.1074/jbc.M005889200. Epub 2000 Oct 27.


A new member of the Bcl-2 family was identified, Bcl-G. The human BCL-G gene consists of 6 exons, resides on chromosome 12p12, and encodes two proteins through alternative mRNA splicing, Bcl-G(L) (long) and Bcl-G(S) (short) consisting of 327 and 252 amino acids in length, respectively. Bcl-G(L) and Bcl-G(S) have identical sequences for the first 226 amino acids but diverge thereafter. Among the Bcl-2 homology (BH) domains previously recognized in Bcl-2 family proteins, the BH3 domain is found in both Bcl-G(L) and Bcl-G(S), but only the longer Bcl-G(L) protein possesses a BH2 domain. Bcl-G(L) mRNA is expressed widely in adult human tissues, whereas Bcl-G(S) mRNA was found only in testis. Overexpression of Bcl-G(L) or Bcl-G(S) in cells induced apoptosis although Bcl-G(S) was far more potent than Bcl-G(L). Apoptosis induction by Bcl-G(S) depended on the BH3 domain and was suppressed by coexpression of anti-apoptotic Bcl-X(L) protein. Bcl-X(L) also coimmunoprecipitated with Bcl-G(S) but not with mutants of Bcl-G(S) in which the BH3 domain was deleted or mutated or with Bcl-G(L). Bcl-G(S) was predominantly localized to cytosolic organelles, whereas Bcl-G(L) was diffusely distributed throughout the cytosol. A mutant of Bcl-G(L) in which the BH2 domain was deleted displayed increased apoptotic activity and coimmunoprecipitated with Bcl-X(L), suggesting that the BH2 domain autorepresses Bcl-G(L).

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Alternative Splicing
  • Amino Acid Sequence
  • Apoptosis / genetics*
  • Cell Compartmentation
  • Chromosomes, Human, Pair 1
  • Cytosol
  • DNA, Complementary / genetics
  • Exons
  • Genes, bcl-2*
  • Humans
  • Molecular Sequence Data
  • Organelles
  • Protein Structure, Tertiary
  • Proto-Oncogene Proteins c-bcl-2 / genetics*
  • Sequence Analysis, DNA


  • BCL2L14 protein, human
  • DNA, Complementary
  • Proto-Oncogene Proteins c-bcl-2

Associated data

  • GENBANK/AF281254
  • GENBANK/AF281255