Variant of perivitelline membrane glycoprotein ZPC of Japanese quail (Coturnix japonica) lacking its cytoplasmic tail exhibits the retention in the endoplasmic reticulum of Chinese hamster ovary (CHO-K1) cells.
Avian perivitelline membrane, an investment homologous to the mammalian zona pellucida, is composed of at least two glycoproteins. Our previous studies demonstrated that one of its components, ZPC, which is synthesized in the ovarian granulosa cells, is secreted after carboxy-terminal proteolytic processing, and this event is a prerequisite event for ZPC secretion in quail. In the present study, we examined the role of the cytoplasmic tail, which is successfully removed after proteolytic processing, in membrane transport, proteolytic processing, and the secretion of quail ZPC. In pursuit of this, we produced a truncated ZPC mutant lacking the cytoplasmic tail located in its C-terminus and examined its expression in the mammalian cell line. Western blot analyses demonstrated that the cytoplasmic tail-deficient ZPC was neither secreted nor underwent proteolytic processing in the cells. Immunofluorescence analysis and the acquisition of resistance to endoglycosidase H digestion of the cytoplasmic tail-deficient ZPC demonstrated that the deletion of the cytoplasmic tail interferes with the intracellular trafficking of the protein from the endoplasmic reticulum to the Golgi apparatus. These results indicate that the cytoplasmic tail of quail ZPC might possess the determinant responsible for the efficient transport of the newly synthesized ZPC from the endoplasmic reticulum to the Golgi apparatus.
Sasanami
Tomohiro
T
Department of Applied Biological Chemistry, Faculty of Agriculture, Shizuoka University, Shizuoka 422-8529, Japan.
Hanafy
Ahmed M
AM
Toriyama
Masaru
M
Mori
Makoto
M
D000818:Animals; D001693:Biological Transport, Active; D016466:CHO Cells; D003370:Coturnix; D006224:Cricetinae; D003593:Cytoplasm / Q000378:metabolism*; D004527:Egg Proteins / Q000235:genetics / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D005260:Female; D006056:Golgi Apparatus; D006107:Granulosa Cells / Q000737:chemistry; D006596:Hexosaminidases / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D011498:Protein Precursors / Q000235:genetics / Q000378:metabolism; D011956:Receptors, Cell Surface; D014817:Vitelline Membrane / Q000378:metabolism*; D000072216:Zona Pellucida Glycoproteins
D004527:Egg Proteins; D008562:Membrane Glycoproteins; D011498:Protein Precursors; D011956:Receptors, Cell Surface; D000072216:Zona Pellucida Glycoproteins; D006596:Hexosaminidases