Processing and secretion of the N-terminal domain of alpha-dystroglycan in cell culture media.
Alpha-dystroglycan (alpha-DG) plays a crucial role in maintaining the stability of muscle cell membrane. Although it has been shown that the N-terminal domain of alpha-DG (alpha-DG-N) is cleaved by a proprotein convertase, its physiological significance remains unclear. We show here that native alpha-DG-N is secreted by a wide variety of cultured cells into the culture media. The secreted alpha-DG-N was both N- and O-glycosylated. Finally, a small amount of alpha-DG-N was detectable in the normal human serum. These observations indicate that the cleavage of alpha-DG-N is a widespread event and suggest that the secreted alpha-DG-N might be transported via systemic circulation in vivo.
Saito
Fumiaki
F
Department of Neurology and Neuroscience, Teikyo University School of Medicine, 2-11-1 Kaga, Itabashi-ku, Tokyo 173-8605, Japan.
Saito-Arai
Yuko
Y
Nakamura
Ayami
A
Shimizu
Teruo
T
Matsumura
Kiichiro
K
D000818:Animals; D000906:Antibodies / Q000737:chemistry / Q000302:isolation & purification; D019556:COS Cells; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D003470:Culture Media / Q000737:chemistry / Q000378:metabolism*; D049030:Dystroglycans / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D006031:Glycosylation; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D011499:Protein Processing, Post-Translational; D017434:Protein Structure, Tertiary; D044967:Serum / Q000737:chemistry / Q000378:metabolism
D000906:Antibodies; D003470:Culture Media; D049030:Dystroglycans