Increased methylation of the cytosolic 20-kD protein is accompanied by liver regeneration in a hepatectomized rat.
- Author:
Soon Young KWON
1
;
Sohee KIM
;
Kyounghwa LEE
;
Tae Jin KIM
;
Seung Hoon LEE
;
Kyung Mi LEE
;
Gil Hong PARK
Author Information
1. Department of Otolaryngology-Head and Neck Surgery, College of Medicine, Korea University, Ansan 425-707, Korea.
- Publication Type:Original Article ; Research Support, Non-U.S. Gov't
- Keywords:
arginine N-methylation;
cytosolic 20-kDa protein;
histone;
regenerating rat liver
- MeSH:
Animals;
Cytoplasm/*chemistry;
*Hepatectomy;
Histones/metabolism;
Humans;
Liver Regeneration/*physiology;
Methylation;
Methyltransferases/metabolism;
Protein Isoforms/metabolism;
Proteins/*metabolism;
Rats;
Rats, Sprague-Dawley;
Research Support, Non-U.S. Gov't;
Signal Transduction/physiology;
Subcellular Fractions/chemistry/metabolism
- From:Experimental & Molecular Medicine
2004;36(1):85-92
- CountryRepublic of Korea
- Language:English
-
Abstract:
Arginine methylation has been implicated in the signal transduction pathway leading to cell growth. Here we show that a regenerating rat liver following partial hepatectomy exhibited elevated methyltransferase activity as shown by increased methylation of a subset of endogenous proteins in vitro. The 20-kDa protein was shown to be a major cytosolic protein undergoing methylation in regenerating hepatocytes. Methylation of the 20-kDa protein peaked at 1 d following partial hepatectomy, which gradually declined to a basal level within the next 14 d. Likewise, methylation of exogenously added bulk histones followed the similar time kinetics as the 20-kDa protein, reflecting time-dependent changes in methyltransferase activity in regenerating hepatocytes. Presence of exogenously added bulk histone in the in vitro methylation assay resulted in dose-dependent inhibition of methylation of the 20-kDa protein. All the histone subtypes tested, histone 1, 2A, 2B, 3 or 4, were able to inhibit methylation of the 20-kDa protein while addition of cytochrome C, a-lactalbumin, carbonic anhydrase, bovine serum albumin, and g globulin minimally affected methylation of the 20-kDa protein. Since methylation of the 20-kDa protein preceded proliferation of hepatocytes upon partial hepatectomy, it is tempting to speculate that the methylated 20-kDa protein by activated histone-specific methyltransferase may be involved in an early signal critical for liver regeneration.
