Arrest of proteolipid transport through the Golgi apparatus in Jimpy brain.
Immunocytochemical investigations were performed on Jimpy and control mouse brains using three specific anti-myelin proteolipids antisera: immunoaffinity purified multivalent anti-(PLP + DM-20) proteolipid antibodies, anti-C-terminal hexapeptide 271-276 and anti-tridecapeptide 117-129 antisera. The results show that oligodendrocytes and myelin sheaths in normal mouse brain are labelled to the same extent by the three specific antisera; in contrast, in Jimpy brain these cellular structures are only stained by the multivalent antibodies and the site-specific, anti-tridecapeptide antiserum. The absence of labelling with C-terminal hexapeptide antiserum in mutant brain is interpreted as the result of either a large deletion or a point mutation producing a frameshift in the C-terminal part of the sequences of the proteolipids PLP and DM-20. Furthermore, we show that this mutation prevents the normal transport of proteolipid molecules through the Golgi apparatus. The existence of a minor, extra-Golgi apparatus metabolic route for proteolipids to myelin structures is also discussed.
Roussel
G
G
Neskovic
N M
NM
Trifilieff
E
E
Artault
J C
JC
Nussbaum
J L
JL
D000818:Animals; D001692:Biological Transport; D001921:Brain / Q000378:metabolism*; D006056:Golgi Apparatus / Q000378:metabolism*; D007124:Immunoenzyme Techniques; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008816:Mice, Jimpy / Q000378:metabolism*; D008818:Mice, Neurologic Mutants / Q000378:metabolism*; D008854:Microscopy, Electron; D009185:Myelin Proteins / Q000378:metabolism*; D009186:Myelin Sheath / Q000378:metabolism; D009836:Oligodendroglia / Q000378:metabolism; D011510:Proteolipids / Q000378:metabolism*
D009185:Myelin Proteins; D011510:Proteolipids