Increased lysine N-methylation of a 23-kDa protein during hepatic regeneration.
The methylation of a 23-kDa nuclear protein increased after partial hepatectomy and methylation returned to basal levels after the initial stage of regeneration. The methylating enzyme was partially purified from rat liver by ammonium sulfate precipitation, DEAE-anion exchange chromatography and Butyl-Sepharose chromatography. The 23-kDa protein was purified from a nuclear fraction of liver tissue with SP-Sepharose. When the 23-kDa protein was methylated with the partially purified methyltransferase and analyzed on C(18) high performance liquid chromatography (HPLC), the methylated acceptor amino acid was monomethyl lysine (MML). Previously, only arginine N-methylation of specific substrate proteins has been reported during liver regeneration. However, in this report, we found that lysine N-methylation increased during early hepatic regeneration, suggesting that lysine N-methylation of the 23-kDa nuclear protein may play a functional role in hepatic regeneration. The methyltransferase did not methylate other proteins such as histones, hnRNPA1, or cytochrome C, suggesting the enzyme is a 23-kDa nuclear protein- specific lysine N-methyltransferase.
Choi
Yong-Bock
YB
Department of Biochemistry, Chunbuk National University, Cheonju 561-756, Korea.
Ko
Myoung-Hyun
MH
Shin
Chang-Ho
CH
Kim
Kyung-Suk
KS
Hong
Kyeong-Man
KM
Paik
Moon-Kee
MK
Park
Dong-Eun
DE
D000818:Animals; D045304:Cytochromes c / Q000378:metabolism; D004265:DNA Helicases / Q000378:metabolism; D006498:Hepatectomy; D011495:Histone-Lysine N-Methyltransferase / Q000378:metabolism*; D006657:Histones / Q000378:metabolism; D008099:Liver; D008115:Liver Regeneration / Q000502:physiology*; D008239:Lysine / Q000378:metabolism*; D008745:Methylation; D011506:Proteins / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley
D006657:Histones; D011506:Proteins; C027729:helix-destabilizing proteins; D045304:Cytochromes c; D011495:Histone-Lysine N-Methyltransferase; D004265:DNA Helicases; D008239:Lysine