CHARACTERIZATION OF HUMAN AND RAT-BRAIN MYRISTOYL-COA-PROTEIN N-MYRISTOYLTRANSFERASE - EVIDENCE FOR AN ALTERNATIVE SPLICE VARIANT OF THE ENZYME

Using 5'-rapid amplification of cDNA ends, we have identified an exten ded 5'-end of mRNA coding for human myristoyl-CoA:protein N-myristoylt ransferase (NMT). PCR using primers based on this new 5'-sequence and reverse primers within the currently accepted coding sequence of the e nzyme resulted in the identification of a novel splice variant of NMT. In vitro translation of these cDNAs resulted in the production of pro teins with apparent molecular masses of 63 kDa and 48 kDa. Immunopreci pitation of NMT from human cell lines and immunoblotting of a range of rat tissues has identified proteins with molecular masses correspondi ng to those derived from these cDNAs, and provided evidence that their relative abundance differs among tissues. Our results provide evidenc e that this enzyme exists in different forms resulting from alternativ e splicing of the mRNA.