암세포의 증식과정에서 20 kDa 단백질의 arginine 메칠화 반응에 관한 연구

초록

Enzymatic methylation of endogenous protein (s) by protein arginine N-methyl- transferase (EC. 2.1.1.23) in several cancer cell lines was investigated in an attempt to understand possible regulatory role of the modification in relation to cellular proliferation. When several cancer cells (HeLa, HCT-48, A549, HepG2) were incubated with S-adenosyl-L-methyl-'Hmethionine. the endogenous 20- kDa species in the extracts were most intensely (methyl-H)-labeled compared to that in normal colon tissues. Whether the (methyl-'H)-labeld 20-kDa is due to carboxyl-O-methylation, the alkali-lability of the purified and methylated 20- kDa species were examined at pH 9-11. at 37°C for 60 min. The results indicated that (methyl-*H)-label on the 20-kDa species of HCT-48 cells did not decrease after alkali treatment quantified by Fuji BAS 2500 Bio-Image analyzer. The methylation of 20-kDa did not increase in the presence of 4 mM GTPYS, further indicating the methylation is not due to C-terminal farnesylated cysteine car- boxyl methylation. Also, none of purified histones showed the same mobility on SDS-PAGE as the 20-kDa endogenous substrate. In conclusion, in the present study, a new novel endogenous 20-kDa methyl accepting protein for protein argi- nine methyltransferase was found which is closely correlated with cell prolifera- tion suggesting a possible role of this post-translational modification during cel- lular proliferation.

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