An alternatively spliced long form of Fas apoptosis inhibitory molecule (FAIM) with tissue-specific expression in the brain

The gene encoding Fas apoptosis inhibitory molecule (FAIM) was cloned by di fferential display using RNA obtained from Fas-resistant and Fas-sensitive primary murine B lymphocytes. FAIM is highly evolutionarily conserved and b roadly expressed, suggesting that its gene product plays a key role in cell ular physiology. Here we report the identification of a new, longer form of FAIM (FAIM-L) and characterization of the genomic locus that clarifies its origin. The murine FAIM gene is located at chromosome 9fl, a region synten ic to the corresponding location of the human FAIM gene. The gene consists of six exons and contains putative translation initiation sites within exon s II and III. The long form of FAIM is generated by all six exons, whereas the originally cloned form of FAIM, now termed FAIM-Short (FAIM-S) is gener ated from five exons by alternative splicing. FAIM-L is dominantly expresse d in the brain whereas FAIM-S is widely expressed in many tissues. (C) 2001 Elsevier Science Ltd. All rights reserved.