Splice site selection in the proteolipid protein (PLP) gene transcript and primary structure of the DM-20 protein of central nervous system myelin.
Proteolipid protein (PLP) is the major myelin membrane protein of the central nervous system. We have isolated a copy of an alternatively spliced PLP gene transcript from a mouse brain cDNA library that was screened for PLP-related sequences. The encoded 241-amino acid protein differs from PLP by an internal deletion of 35-amino acid residues (116-150) from the major hydrophilic domain. This PLP variant is identical with the DM-20 protein of myelin, previously described as a brain-specific myelin component and known to be related to PLP. We determined the corresponding nucleotide sequence of the rat PLP gene and found that DM-20 mRNA results when a second 5' splice site, located 105 nucleotides within the third exon of the primary PLP transcript, is utilized in precursor mRNA (pre-mRNA) splicing. This demonstrates that alternative 5' splice site selection can determine the protein product of a cellular gene. DM-20 mRNA is expressed in rat brain with approximately 50% abundance relative to PLP mRNA and appears to be developmentally coregulated.
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D051379:Mice; D008816:Mice, Jimpy; D009185:Myelin Proteins / Q000032:analysis / Q000235:genetics*; D018991:Myelin Proteolipid Protein; D009186:Myelin Sheath / Q000502:physiology; D009419:Nerve Tissue Proteins; D011487:Protein Conformation; D011510:Proteolipids / Q000032:analysis / Q000235:genetics*; D012326:RNA Splicing; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D014158:Transcription, Genetic
D009185:Myelin Proteins; D018991:Myelin Proteolipid Protein; D009419:Nerve Tissue Proteins; C047516:Plp1 protein, mouse; C489071:Plp1 protein, rat; D011510:Proteolipids; D012333:RNA, Messenger