Increased contractile activity decreases rna-protein interaction in
the 3_-untranslated region of cytochrome c mrna.
Yan, Zhen, Stanley Salmons, Yan Li Dang, Marc T. Hamilton, and Frank
W. Booth.
Department of Integrative Biology, University of Texas Medical
School, Houston, TX 77225, U.S.A., Department of Human Anatomy and
Cell Biology, University of Liverpool, Liverpool L69 3BX, U.K.
APStracts 3:0192C, 1996.
This study was designed to gain an insight into mechanisms by which
cytochrome?c gene expression is enhanced by increased contractile
activity in skeletal muscle. When rat TA muscles were stimulated (10
Hz, 0.25?ms) for 0, 2, 6, 12, 24 hr, 2, 5, 9 or 13 days (n?=?4 for
each time point), cytochrome c protein (enzyme-linked immunosorbent
assay) and mRNA (Northern blot analysis) concentrations started to
increase by 9 days, and this was associated with concurrent decreases
in cytochrome c mRNA-protein interaction (RNA gel mobility shift
assay). We found that the decreased RNA-protein interaction in the
stimulated muscle extract was restored by ultracentrifugation
(150,000 _ g, 1 h) in the supernatant fraction. The 150,000 g pellet
fraction of stimulated muscle was capable of inhibiting the RNA
-protein interaction in control TA muscles. These results provide
evidence of an inhibitory factor that is responsible for decreasing
RNA-protein interaction in the 3_-UTR of cytochrome c mRNA in
continuously stimulated muscle.
Received 1 December 1995; accepted in final form 4 April 1996.
APS Manuscript Number C719-5.
Article publication pending Am. J. Physiol. (Cell Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 28 June 96