A novel splicing variant of mouse interleukin (IL)-24 antagonizes IL-24-induced apoptosis.
Alternative splicing of mRNA enables functionally diverse protein isoforms to be expressed from a single gene, allowing transcriptome diversification. Interleukin (IL)-24/MDA-7 is a member of the IL-10 gene family, and FISP (IL-4-induced secreted protein), its murine homologue, is selectively expressed and secreted by T helper 2 lymphocytes. A novel splice variant of mouse IL-24/FISP, designated FISP-sp, lacks 29 nucleotides from the 5'-end of exon 4 of FISP. The level of FISP-sp expression is 10% of the level of total primary FISP transcription. Unlike FISP, FISP-sp does not induce growth inhibition and apoptosis. FISP-sp is exclusively localized in endoplasmic reticulum, and its expression is up-regulated by endoplasmic reticulum stress. Our results suggest that the novel splicing variant FISP-sp dimerizes with FISP and blocks its secretion and inhibits FISP-induced apoptosis in vivo.
Sahoo
Anupama
A
Department of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, Korea.
Jung
Yun Min
YM
Kwon
Ho-Keun
HK
Yi
Hwa-Jung
HJ
Lee
Suho
S
Chang
Sunghoe
S
Park
Zee-Yong
ZY
Hwang
Ki-Chul
KC
Im
Sin-Hyeog
SH
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis; D001483:Base Sequence; D019556:COS Cells; D002522:Chlorocebus aethiops; D016207:Cytokines / Q000235:genetics* / Q000378:metabolism*; D019281:Dimerization; D004721:Endoplasmic Reticulum / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008546:Melanoma, Experimental; D051379:Mice; D008954:Models, Biological; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid; D000099180:Interleukin-24
D016207:Cytokines; C431904:Il24 protein, mouse; D000099180:Interleukin-24