Expression of the amino acid dimorphism in the small myelin-associated glycoprotein cytoplasmic domain in rat peripheral nerves during postnatal development.
The myelin-associated glycoprotein (MAG) is one of the proteins expressed during the period of myelin formation and is believed to play a major role in the initiation of myelination. It exists as two differentially expressed isoforms, L- and S-MAG, that are generated by alternative mRNA splicing. A nucleotide dimorphism at the mRNA level resulting in an Arg/Pro dimorphism in the cytoplasmic tail of the S-MAG protein has previously been detected in the rat brain. In this study, we show that this dimorphism is detectable in the rat peripheral nervous system. We propose an allelic origin for the dimorphism and demonstrate the differential expression of the S-MAG alleles in the sciatic nerves of heterozygous rats during the period of active myelination. We also present data on the properties of the two S-MAG cytoplasmic domains produced as GST fusion proteins. The importance of this differentially expressed amino acid dimorphism is discussed, taking into account both its probable effect on the S-MAG cytoplasmic domain function and its significance in functional and structural studies concerning the S-MAG protein.
Kursula
P
P
Biocenter Oulu and Department of Pathology, University of Oulu, Kajaanintie 52 D, FIN-90220 Oulu, Finland. petri.kursula@oulu.fi
Lehto
V P
VP
Garbay
B
B
Cassagne
C
C
Heape
A M
AM
D000596:Amino Acids / Q000032:analysis*; D000818:Animals; D001120:Arginine / Q000032:analysis; D018992:Myelin-Associated Glycoprotein / Q000737:chemistry*; D010766:Phosphorylation; D016133:Polymerase Chain Reaction / Q000379:methods; D011392:Proline / Q000032:analysis; D017434:Protein Structure, Tertiary; D051381:Rats; D017207:Rats, Sprague-Dawley; D011993:Recombinant Fusion Proteins / Q000032:analysis / Q000096:biosynthesis; D012584:Sciatic Nerve / Q000737:chemistry* / Q000254:growth & development; D017421:Sequence Analysis; D017422:Sequence Analysis, DNA; D014158:Transcription, Genetic
D000596:Amino Acids; D018992:Myelin-Associated Glycoprotein; D011993:Recombinant Fusion Proteins; D001120:Arginine; D011392:Proline