Reciprocal expression of myelin-associated glycoprotein splice variants in the adult human peripheral and central nervous systems.
The L- and S-MAG isoforms differ only at their C-terminus and are believed to be functionally distinct. To obtain information on the relative expression of these alternatively spliced isoforms in humans, we cloned an S-MAG cDNA fragment. The deduced amino-acid sequence of the human S-MAG C-terminus shows fairly conservative substitutions of 4 out of the 10 residues compared to the rodent peptide. Using reverse transcription and a competitive polymerase chain reaction, we show that, in contrast to rodents, the L-MAG splice variant predominates in adult human brain while, like in rodents, S-MAG transcripts are most abundant in peripheral nerve. The results obtained by Western blot analysis and immunohistochemistry are in good agreement with the findings at the mRNA level. Animal experiments may thus be more representative for the role of MAG in human nerve than in brain.
Miescher
G C
GC
Department of Clinical Neurology, University Hospitals, Basle, Switzerland. miescher1@ubaclu.unibas.ch
Lützelschwab
R
R
Erne
B
B
Ferracin
F
F
Huber
S
S
Steck
A J
AJ
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002490:Central Nervous System / Q000378:metabolism*; D019976:Cloning, Organism; D017124:Conserved Sequence; D017931:DNA Primers; D005260:Female; D014644:Genetic Variation; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D018992:Myelin-Associated Glycoprotein / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D017933:Peripheral Nervous System / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism; D012377:Rodentia; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid
D017931:DNA Primers; D018992:Myelin-Associated Glycoprotein; D012333:RNA, Messenger