Identification of a mitogen-activated protein kinase site in human myelin basic protein in situ.
Ultrastructural localization of a specific phosphorylated isomer of myelin basic protein (MBP) has been achieved with a monoclonal antibody specific for human MBP sequence, 89-105, in which Thr98 was phosphorylated. Cryosections of human brain white matter revealed that gold particles were found localized almost exclusively to the major dense line demonstrating that threonine 98 in the sequence Thr-Pro-Arg-Thr-Pro-Pro-Pro, a mitogen-activated protein kinase-specific site, was phosphorylated in vivo. In two cases of multiple sclerosis, the density of gold particles in myelin was reduced by about 30%, in one case by 42%, and by 80% in a fourth case. However, gold labelling was seen in areas of demyelination suggesting that the phosphorylated threonyl peptide was protected from degradation.
Yon
M
M
School of Biological and Molecular Sciences, Oxford Brookes University, Headington, UK.
Ackerley
C A
CA
Mastronardi
F G
FG
Groome
N
N
Moscarello
M A
MA
D000595:Amino Acid Sequence; D000918:Antibody Specificity; D001665:Binding Sites / Q000502:physiology; D001921:Brain / Q000166:cytology; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000737:chemistry / Q000378:metabolism*; D002956:Citrulline / Q000276:immunology; D006801:Humans; D007150:Immunohistochemistry; D008854:Microscopy, Electron; D008934:Mitogens / Q000502:physiology; D008969:Molecular Sequence Data; D009103:Multiple Sclerosis / Q000378:metabolism; D004676:Myelin Basic Protein / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D009186:Myelin Sheath / Q000737:chemistry / Q000276:immunology / Q000648:ultrastructure; D010766:Phosphorylation; D013912:Threonine / Q000378:metabolism
D008934:Mitogens; D004676:Myelin Basic Protein; D002956:Citrulline; D013912:Threonine; D017871:Calcium-Calmodulin-Dependent Protein Kinases