Phorbol Ester Stimulates Expression of the Human Tryptophanyl-tRNA Synthetase Gene

M. Yu. Zabazarnykh^1,2 and D. Yu. Litvinov³

¹Gabrichevsky Research Institute of Epidemiology and Microbiology, ul. Admirala Makarova 10, Moscow 125212, Russia; fax: (095) 452-1830; E-mail: zabazarn@yahoo.com

²National Creative Research Initiatives Center for ARS Network, College of Pharmacy, Seoul National University, Seoul 151742, South Korea

³Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow 119991, Russia

^* To whom correspondence should be addressed.

Received November 13, 2002; Revision received December 10, 2002

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The effect of the phorbol ester phorbol 12-myristate 13-acetate (PMA) on expression of the human interferon (IFN)-inducible tryptophanyl-tRNA synthetase (WRS) gene was studied. PMA caused an increase in the basal and IFNgamma-induced WRS protein content in HeLa and HEK293 cultured cells. Besides, PMA upregulated WRS mRNA level in HeLa cells. Since PMA is known as a selective activator of protein kinase C (PKC) and is widely used to study the PKC-related pathways, these results show possible PKC involvement in regulation of the WRS gene expression. PKC inhibition by staurosporine (10 and 100 nM) had no effect on either basal or IFNgamma-induced expression of WRS in either cell line. Consequently, PKC is not an indispensable element in WRS induction by IFNgamma. Rather, PKC may activate WRS gene expression only by a distinct pathway.

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KEY WORDS: tryptophanyl-tRNA synthetase, phorbol 12-myristate 13-acetate, interferon, Ap₃A, protein kinase C

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