Increased expression of protein C-mannosylation in the aortic vessels of diabetic Zucker rats.
C-Mannosylation is a novel type of glycosylation in proteins. There are several examples of proteins in which the specific motif Trp-X-X-Trp is mannosylated at the first Trp to produce C-mannosylated Trp (CMW). Although C-mannosylation modifies Trp-X-X-Trp, predicted to be a functional motif of various integral proteins such as cytokine receptors, the physiological or pathological relevance of C-mannosylation in the cell is still not known. In this study, to characterize C-mannosylation in biological samples, we generated specific polyclonal antibodies against CMW by using a chemically synthesized CMW as an antigen. Using the antibody, we investigated the effect of hyperglycemic conditions on protein C-mannosylation in cultured cells and diabetic Zucker fatty rats. We found that protein C-mannosylation was increased in macrophage-like RAW264.7 cells under hyperglycemic conditions compared to low-glucose conditions. Furthermore, C-mannosylation was increased in the aortic vessel wall of Zucker fatty rats. Thrombospondin-1 was identified as a protein modified with C-mannosylation, and its expression was also increased in the aortic tissues of Zucker fatty rats. These results indicate that C-mannosylation is increased in specific tissues or cell types under hyperglycemic conditions, suggesting a pathological role for the increased C-mannosylation in the development of diabetic complications.
Ihara
Yoshito
Y
Department of Biochemistry and Molecular Biology in Disease, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan. y-ihara@net.nagasaki-u.ac.jp
Manabe
Shino
S
Kanda
Munetake
M
Kawano
Hiroaki
H
Nakayama
Toshiyuki
T
Sekine
Ichiro
I
Kondo
Takahito
T
Ito
Yukishige
Y
D020816:Amino Acid Motifs / Q000502:physiology; D000818:Animals; D001011:Aorta / Q000166:cytology / Q000378:metabolism*; D002460:Cell Line; D048909:Diabetes Complications / Q000378:metabolism; D005786:Gene Expression Regulation; D006031:Glycosylation; D008364:Mannosyltransferases / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011924:Rats, Zucker; D019700:Thrombospondin 1 / Q000378:metabolism*
D019700:Thrombospondin 1; D008364:Mannosyltransferases