HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Russell, T. R. Articles by Pastan, I. H. Search for Related Content PubMed PubMed Citation Articles by Russell, T. R. Articles by Pastan, I. H. Social Bookmarking                      What's this?

Cyclic Adenosine 3':5'-Monophosphate and Cyclic Guanosine 3':5'-Monophosphate Phosphodiesterase Activities Are under Separate Genetic Control

From the ¹ From the Laboratory of Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20014

Agents that raise cyclic adenosine 3':5'-monophosphate (cyclic AMP) levels in chicken embryonic fibroblasts increase cyclic AMP phosphodiesterase activity. Cyclic guanosine 3':5'-monophosphate (cyclic GMP) phosphodiesterase activity is not increased indicating that these enzyme activities are under separate regulation. The increase in cyclic AMP phosphodiesterase activity requires cellular protein and RNA synthesis, and the regulation of induction probably occurs at the transcriptional level. The induced cyclic AMP phosphodiesterase activity is very unstable. The enzyme activity decays from the induced level with a half-life of 70 to 80 min.

Increased enzyme activity is found in both the particulate and soluble cell fractions. The particulate enzyme can be solubilized by sonic disruption. DEAE-cellulose chromatography of the solubilized enzyme yields two fractions that hydrolyze cyclic AMP. Induction causes an increase in the activity of the second fraction. Neither of the particulate enzymes hydrolyze cyclic GMP.

DEAE-cellulose chromatography of the soluble enzyme also yields two fractions. The first peak hydrolyzes both cyclic AMP and cyclic GMP and the second only cyclic AMP. Induction increases the activity of the second fraction. Chicken embryonic fibroblasts thus contain mechanisms for effectively modulating cyclic AMP phosphodiesterase activity via protein synthesis and enzyme turnover. Cyclic GMP phosphodiesterase activity is not affected by this regulatory scheme.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?