A cross-talk between RNA splicing and signaling pathway alters Fas gene expression at post-transcriptional level: alternative splicing of Fas mRNA in the leukemic U937 cells.
It is now widely accepted that alternative splicing is a mechanism that is responsible for generating protein complexity at low genetic cost. However, little is known about molecular mechanisms that govern alternative splicing of key apoptotic regulators. Here we investigate the effect of pro-apoptotic stimuli on alternative splicing of Fas mRNA by means of reverse transcription-polymerase chain reaction (RT-PCR). Exposure of U937 cells to etoposide, staurosporine, pacritaxel, or cyclohexamide promoted the appearance of the splice variant, which retained the 152-base-pair intron 5. Pretreatment with calyculin A, an inhibitor of protein phosphatase-1 (PP-1) as well as fumonisin B1, an inhibitor of ceramide synthase, prevented etoposide-induced alternative splicing of Fas mRNA. Our data demonstrate that cross-talk between RNA splicing and signaling pathways through endogenous ceramide synthesis and subsequent phosphatase activation is a mechanism that modifies Fas gene expression at the posttranscriptional level.
Aratake
Kouichiro
K
First Department of Internal Medicine, Graduate School of Biomedical Science, Nagasaki University, 1-7-1 Sakamoto, Nagasaki 852-8501, Japan.
Kamachi
Makoto
M
Iwanaga
Nozomi
N
Kawasaki
Eiji
E
Izumi
Yasumori
Y
Ida
Hiroaki
H
Tanaka
Fumiko
F
Tamai
Mami
M
Arima
Kazuhiko
K
Nakamura
Hideki
H
Origuchi
Tomoki
T
Kawakami
Atsushi
A
Eguchi
Katsumi
K
D017398:Alternative Splicing / Q000187:drug effects / Q000502:physiology*; D000970:Antineoplastic Agents / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D020169:Caspases / Q000378:metabolism; D002518:Ceramides / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic / Q000502:physiology*; D006801:Humans; D007938:Leukemia / Q000378:metabolism; D012323:RNA Processing, Post-Transcriptional / Q000187:drug effects / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism; D018124:Receptors, Tumor Necrosis Factor / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology; D020298:U937 Cells; D019014:fas Receptor
D000970:Antineoplastic Agents; D002518:Ceramides; C491901:FAS protein, human; D012333:RNA, Messenger; D018124:Receptors, Tumor Necrosis Factor; D019014:fas Receptor; D020169:Caspases