Nucleic Acids Research, 1980, Vol. 8, No. 17 3841-3850
© 1980
MOLECULAR BIOLOGY |
Post-transcriptional modification of the poly(A) length of galactose-1-phosphate uridyl transferase mRNA in Saccharomyces cerevisiae
Department of Biology and Rosenstiel Basic Medical Sciences Research Center, Brandeis University Waltham, MA 02254, USA
+ To whom correspondence should be addressed
Received May 16, 1980.
Thermal elution poly(U)-Sepharose chromatography was utilized to fractionate yeast mRNA based on poly(A) size. Analysis of the in vitro translation products of the fractionated RNAs in a wheat-embryo cell-free protein synthesis system shows a heterogeneous but equal distribution of these abundant translatable mRNAs in the different poly(A) size classes. By comparing the translational activity of inducible galactose-1-phosphate uridyl transferase mRNA, which can be monitored as a function of age, to contitutive mRNAs, we demonstrate that initially galactose-1-phosphate uridyl transferase mRNA has a uniformly large poly(A) tail which becomes heterogeneous and shorter with age in the cytoplasm. These observations are consistent with the previously observed cytoplasmic poly(A) catabolism in yeast and with cytoplasmic post-transcriptional modification of the poly(A) length of galactose-1-phosphate uridyl transferase mRNA.
*Present address: Department of Biophysics, Oregon State University, Corvallis, Oregon 97731.