Rapid increase of cytosolic content of acetyl-CoA carboxylase isoforms in H9c2 cells by short-term treatment with insulin and okadaic acid.
- Author:
Chang Eun PARK
1
;
Sun Min KO
;
Jung Mok KIM
;
Moon Young YOON
;
Ja Young KIM
;
In Sug KANG
;
Sung Soo KIM
;
Joo Hun HA
Author Information
1. Department of Molecular Biology, College of Medicine, Kyung Hee University, Seoul, Korea.
- Publication Type:Original Article ; Research Support, Non-U.S. Gov't
- Keywords:
acetyl-CoA carboxylase;
carnitine palmitoyltransferase-I;
malonyl-CoA;
digitonin;
H9c2 cardiac myocyte.
- MeSH:
Acetyl-CoA Carboxylase/metabolism*;
Acetyl-CoA Carboxylase/drug effects;
Animal;
Cell Differentiation/drug effects;
Cell Line;
Cell Membrane Permeability;
Chromones/pharmacology;
Cytosol/enzymology*;
Cytosol/drug effects;
Digitonin/pharmacology;
Immunoblotting;
Insulin/pharmacology*;
Isoenzymes;
Morpholines/pharmacology;
Myocardium/cytology;
Okadaic Acid/pharmacology*;
Phosphorylation;
Rats
- From:Experimental & Molecular Medicine
1998;30(2):73-79
- CountryRepublic of Korea
- Language:English
-
Abstract:
Mammalian acetyl-CoA carboxylase (ACC) is present in two isoforms, alpha and beta, both of which catalyze formation of malonyl-CoA by fixing CO2 into acetyl-CoA. ACC-alpha is highly expressed in lipogenic tissues whereas ACC-beta is a predominant form in heart and skeletal muscle tissues. Even though the tissue-specific expression pattern of two ACC isoforms suggests that each form may have a distinct function, existence of two isoforms catalyzing the identical reaction in a same cell has been a puzzling question. As a first step to answer this question and to identify the possible role of ACC isoforms in myogenic differentiation, we have investigated in the present study whether the expression and the subcellular distribution of ACC isoforms in H9c2 cardiac myocyte change so that malonyl-CoA produced by each form may modulate fatty acid oxidation. We have observed that the expression levels of both ACC forms were correlated to the extent of myogenic differentiation and that they were present not only in cytoplasm but also in other subcellular compartment. Among the various tested compounds, short-term treatment of H9c2 myotubes with insulin or okadaic acid rapidly increased the cytosolic content of both ACC isoforms up to 2 folds without affecting the total cellular ACC content. Taken together, these observations suggest that both ACC isoforms may play a pivotal role in muscle differentiation and that they may translocate between cytoplasm and other subcellular compartment to achieve its specific goal under the various physiological conditions.
