The M1 and M2 subunits of rat pyruvate kinase are encoded by different messenger RNAs.
The question of whether the M1- and M2-type isozymes of pyruvate kinase are synthesized by a common mRNA was examined by isolating total RNA from rat skeletal muscle and AH-130 Yoshida ascites hepatoma cells, which express the M1- and M2-type isozymes, respectively, and translating the preparations in a rabbit reticulocyte lysate system. The newly synthesized pyruvate kinase subunits were compared by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and isoelectric focusing under the denaturing condition. The pyruvate kinase subunit synthesized from hepatoma cell RNA had a slightly larger molecular weight and higher pI value than the subunit from muscle RNA. When a mixture of the two RNAs was added to the lysate, the same result was obtained. Thus, it is concluded that the M1- and M2-type isozymes are translated from different messenger RNAs.
D000818:Animals; D004591:Electrophoresis, Polyacrylamide Gel; D007527:Isoenzymes / Q000235:genetics*; D008114:Liver Neoplasms, Experimental / Q000201:enzymology*; D046911:Macromolecular Substances; D009132:Muscles / Q000201:enzymology*; D014176:Protein Biosynthesis; D011770:Pyruvate Kinase / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics*; D011817:Rabbits; D051381:Rats; D012156:Reticulocytes / Q000378:metabolism
D007527:Isoenzymes; D046911:Macromolecular Substances; D012333:RNA, Messenger; D011770:Pyruvate Kinase