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Effects of Ara‐C on neutral sphingomyelinase and mitogen‐and stress‐activated protein kinases in T‐lymphocyte cell lines
Author(s) -
Bradshaw Cynthia D.,
Ella Krishna M.,
Thomas Aydrian L.,
Qi Chen,
Meier Kathryn E.
Publication year - 1996
Publication title -
iubmb life
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.132
H-Index - 113
eISSN - 1521-6551
pISSN - 1521-6543
DOI - 10.1080/15216549600201313
Subject(s) - jurkat cells , ceramide , sphingomyelin , ionomycin , mapk/erk pathway , microbiology and biotechnology , kinase , protein kinase a , mitogen activated protein kinase , protein kinase c , cell culture , chemistry , biology , t cell , biochemistry , apoptosis , immunology , intracellular , membrane , immune system , genetics
Neutral sphingomyelinase (SMase)1 can be activated by extracellular signals to produce ceramide, which may affect mitogen‐activated protein kinase (MAPK) activities. Neutral SMase activity was assessed in membranes from Jurkat, a human T‐cell line, and EL4, a murine T‐cell line. Ara‐C activated SMase within 10 minutes in both Jurkat and EL4 cells, while phorbol ester (PMA) had no effect. PMA, but not Ara‐C or ceramides, activated ERK MAPKs in Jurkat and EL4. PMA acted synergistically with ionomycin to activate JNK MAPKs in Jurkat and EL4 within 10 minutes. Ara‐C activated JNKs only after prolonged incubation (90‐120 minutes). Thus, ceramide is not a positive signal for ERK activation in T‐cell lines. The effects of Ara‐C on JNK activity may be mediated through secondary response pathways.