E. Ayroldi et al., Cloning and expression of a short Fas ligand: A new alternatively spliced product of the mouse Fas ligand gene, BLOOD, 94(10), 1999, pp. 3456-3467
The Fas/FasL system mediates apoptosis in several different cell types, inc
luding T lymphocytes. Fas ligand (Fast), a 40-kD type II membrane protein a
lso expressed in activated T cells, belongs to the tumor necrosis factor li
gand family. We describe a new alternative splicing of mouse Fast, named Fa
st short (FasLs), cloned by reverse transcriptase-polymerase chain reaction
. Fasts is encoded by part: of exon 1 and part of exon 4 of Fast gene. The
protein encoded by Fasts mRNA has a putative initiation code at position 75
6 and preserves the same reading frame as Fast, resulting in a short molecu
le lacking the intracellular, the transmembrane, and part of the extracellu
lar domains. RNase protection and immunoprecipitation analysis showed that
Fasts is expressed in nonactivated normal spleen cells and in hybridoma T c
ells and that it is upregulated upon activation by anti-CD3 monoclonal anti
body (MoAb). Moreover, FasLs-transfected cells expressed soluble Fasts in t
he supernatant and became resistant to apoptosis induced by agonist anti-Fa
s MoAb. Thus, Fasts, a new alternative splicing of Fast, is involved in the
regulation of Fas/FasL-mediated cell death. (C) 1999 by The American Socie
ty of Hematology.