Unraveling the differential expression of the two isoforms of myelin-associated glycoprotein in a mouse expressing GFP-tagged S-MAG specifically regulated and targeted into the different myelin compartments.
The two myelin-associated glycoprotein (MAG) isoforms are cell adhesion molecules that differ only in their cytoplasmic domains, but their specific roles are not well understood. In this study, we present a transgenic mouse line that specifically expresses GFP-tagged S-MAG correctly regulated and targeted into the myelin sheath allowing the specific discrimination of L- and S-MAG on the subcellular level. Here, we describe the differential expression pattern and spatial distribution of L- and S-MAG during development as well as in the adult central and peripheral nervous system. In peripheral nerves, where S-MAG is the sole isoform, we observed S-MAG concentrated in different ring-like structures such as periaxonal and abaxonal rings, and discs spanning through the compact myelin sheath perpendicular to the axon. In summary, our data provide new insight in the subcellular distribution of the two isoforms fundamental for the understanding of their specific functions in myelin formation and maintenance.
Erb
Michael
M
Neurobiology, Department of Research, University Hospital Basel, Pharmacenter 7007, Klingelbergstrasse 50/70, CH-4056 Basel, Switzerland.
Flueck
Bettina
B
Kern
Frances
F
Erne
Beat
B
Steck
Andreas J
AJ
Schaeren-Wiemers
Nicole
N
D000818:Animals; D001369:Axons / Q000378:metabolism / Q000648:ultrastructure; D001921:Brain / Q000166:cytology / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D008954:Models, Biological; D009186:Myelin Sheath / Q000378:metabolism* / Q000648:ultrastructure; D018992:Myelin-Associated Glycoprotein / Q000235:genetics / Q000378:metabolism*; D010525:Peripheral Nerves / Q000166:cytology / Q000378:metabolism; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism*; D012584:Sciatic Nerve / Q000166:cytology / Q000378:metabolism
D018992:Myelin-Associated Glycoprotein; D020033:Protein Isoforms; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins