N-linked glycosylation of the human Ca2+ receptor is essential for its expression at the cell surface

G. Fan, P. K. Goldsmith, R. Collins, C. K. Dunn, K. J. Krapcho, K. V. Rogers, A. M. Spiegel

Research output: Contribution to journalArticlepeer-review

77 Scopus citations


The human Ca2+ receptor (hCaR) is a member of the superfamily of G protein-coupled receptors. Its large (~600 residue) amino-terminal extracellular domain contains 9 potential N-linked glycosylation sites. Immunoblot of cell membranes derived from HEK-293 cells, stably transfected with the hCaR, showed two major immunoreactive bands of approximately 150 and 130 kDa, respectively. Complete digestion of the membranes with PN- glycosidase F yielded a single major immunoreactive band of approximately 115 kDa, confirming the presence of N-linked glycosylation. Treatment of these cells with tunicamycin, which blocks N-linked glycosylation, inhibited signal transduction in response to Ca2+. Flow cytometric analysis showed decreased expression of the hCaR on the cell membrane in tunicamycin-treated cells. Immunoblot of tunicamycin-treated cells showed a reduction in the amount of the 150-kDa band and conversion of the 130-kDa band to the presumptively nonglycosylated 115-kDa form. Tunicamycin treatment of cells, transfected with a mutant hCaR complementary DNA containing a nonsense codon at position 599 preceding the 1st transmembrane domain, blocked the secretion of a 95- kDa protein, representing the amino-terminal extracellular domain, into the medium. These results demonstrate that N-linked glycosylation is required for normal expression of the hCaR at the cell surface.

Original languageEnglish (US)
Pages (from-to)1916-1922
Number of pages7
Issue number5
StatePublished - 1997
Externally publishedYes

ASJC Scopus subject areas

  • Endocrinology


Dive into the research topics of 'N-linked glycosylation of the human Ca2+ receptor is essential for its expression at the cell surface'. Together they form a unique fingerprint.

Cite this