J. Biol. Chem., Vol. 260, Issue 10, 5863-5866, May, 1985
RNA directed synthesis of catalytically active Drosophila sn-glycerol-3- phosphate dehydrogenase in Xenopus oocytes
DA Wright, JB Shaffer and GC Bewley
Xenopus laevis oocytes injected with poly(A)+ RNA isolated from Drosophila
melanogaster direct the synthesis of catalytically active
glycerol-3-phosphate dehydrogenase (NAD+) (EC 1.1.1.8). The de novo
synthesized enzyme reflects the electrophoretic properties appropriate to
the stock of flies from which the injected RNA was isolated and is
electrophoretically distinct from endogenous Xenopus activity.
Immunoprecipitation of 35S-labeled translation products has demonstrated
two immunologically related proteins with molecular masses of 32- and 34kDa
which are encoded by two separate mRNA molecules. The 32-kDa protein is
identical in size and charge properties to the protein purified from the
fly and possesses the catalytic activity observed in the Xenopus
translational assay. Poly(A)+ RNA isolated from a strain of flies bearing a
CRM- null mutation at the GPDH locus does not contain translatable RNA for
the 32-kDa protein. These results suggest that the two immunologically
related proteins are the translational products of two separate transcripts
derived from either two related loci or from differential transcription
and/or processing of the same genetic locus.