CSM News
Electronic Edition
Volume 4, number 12
April 1, 1995

Please submit abstracts of your papers as soon as they have been
accepted for publication by sending them to CSM-News@worms.cmsbio.nwu.edu.

Back issues of CSM-News, the CSM Reference database and other useful
information is available by anonymous ftp from worms.cmsbio.nwu.edu
[165.124.233.50], via Gopher at the same address, or by World Wide Web
at the URL "http://worms.cmsbio.nwu.edu/dicty.html"

===========
 Abstracts
===========

CYTOSOLIC NUCLEOSIDE DIPHOSPHATE KINASE ASSOCIATED WITH THE
TRANSLATION APPARATUS MAY PROVIDE GTP FOR PROTEIN SYNTHESIS


Jurgen Sonnemann and Rupert Mutzel, Fakultat fur Biologie
Universitat Konstanz, 78434 Konstanz, Germany

Biochem. Biophys. Res. Commun., in press.

Summary

   Elongation of nascent polypeptides in a Dictyostelium discoideum in
vitro translation system did not require the addition of ATP and GTP
when creatine phosphate and creatine phosphokinase were present.
However, depletion of the exogenous energy supply completely abolished
incorporation of amino acids.  Addition of dTTP, a nucleoside
triphosphate that can be utilized by nucleoside diphosphate kinase
(NDP kinase) to phosphorylate endogenous ADP and GDP, partially
restored protein synthesis. Dictyostelium ribosomes were found to
contain NDP kinase activity that could not be released by 1 M KCl.
Thermal denaturation studies, specific inhibition with antibodies, and
Western blotting identify the activity as cytosolic NDP kinase. These
data support the idea that GTP can be fed into the translation
machinery efficiently by NDP kinase associated with active ribosomes.

--------------------------------------------------------------------
[End CSM News, volume 4, number 12]