Membrane-Associated N-Myristoyltransferase Activity Is Reduced in Obese (fa/fa) Zucker Rat Liver
N-Myristoyltransferase is the enzyme that catalyses the transfer of myristate from myristoyl-CoA to the NH 2-terminal glycine residue of a number of protein of diverse functions. Many of the known myristoylated proteins are important in signal transduction. We have compared the activity of rat liver...
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Published in | Biochemical and biophysical research communications Vol. 196; no. 2; pp. 665 - 670 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
San Diego, CA
Elsevier Inc
29.10.1993
Elsevier |
Subjects | |
Online Access | Get full text |
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Summary: | N-Myristoyltransferase is the enzyme that catalyses the transfer of myristate from myristoyl-CoA to the NH
2-terminal glycine residue of a number of protein of diverse functions. Many of the known myristoylated proteins are important in signal transduction. We have compared the activity of rat liver N-myristoyltransferase from lean and obese (fa/fa) Zucker rats (a model for non-insulin dependent diabetes mellitus, NIDDM). N-myristoyltransferase activity isolated from the particulate fraction of obese (fa/fa) Zucker rat liver was ∼4.7-fold lower than the corresponding activity observed in either the controls or the vanadate-treated obese rat livers. This pattern was only observed in the particulate fraction; the homogenate and soluble N-myristoyltransferase activities were not significantly different to the control activities. N-myristoyltransferase activity isolated from the brain of the four groups showed no significant variations. These results, and previous work [King, M. J., Pugazhenthi, S., Khandelwal, R. L. and Sharma, R. K. (1993) Biochim. Biophys. Acta.
1165, 259-262], would indicate that the rat liver particulate N-myristoyltransferase activity appears to be inversely proportional to the level of plasma insulin, implicating insulin in the control of N-myristoylation. The specific activity of the particulate liver N-myristoyltransferase was approximately 10-fold higher than that of the soluble liver N-myristoyltransferase, raising the possibility that N-myristoyltransferase exists in 2 populations, with the active form of N-myristoyltransferase residing in the membranous fraction. This situation could provide a system whereby N-myristoylation is regulated by the translocation of N-myristoyltransferase from the cytosol to its active site in the membranes. |
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Bibliography: | 9447630 S30 ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0006-291X 1090-2104 |
DOI: | 10.1006/bbrc.1993.2301 |