In:
FEBS Letters, Wiley, Vol. 305, No. 3 ( 1992-07-06), p. 209-212
Abstract:
Like virtually all endocytic receptors, the human asialoglycoprotein (ASGP) receptor is phosphorylated by protein kinase C at serine residues within the cytoplasmic domains of its two subunits H1 and H2. Activation of protein kinase C by phorbol esters results in hyperphosphorylation and in a concomitant net redistribution of receptors to intracellular compartments (down‐regulation) in HepG2 cells. To test whether there is a causal relationship between receptor hyperphosphorylation and redistribution, we examined the effect of phorbol ester treatment on the ASGP receptor composed of either wild‐type subunits or of mutant subunits lacking any cytoplasmic serine residues in transfected NIH3T3 fibroblast and COS‐7 cells. Although the wild‐type subunits were hyperphosphorylated in fibroblast cells, the distribution of neither the wild‐type nor the mutant receptors was affected. In contrast, phorbol ester treatment of transfected COS‐7 cells induced down‐regulation of both wild‐type and mutant receptors. These findings indicate that redistribution of the receptor is independent of its cytoplasmic serines and is not caused by receptor phosphorylation.
Type of Medium:
Online Resource
ISSN:
0014-5793
,
1873-3468
DOI:
10.1016/0014-5793(92)80669-8
Language:
English
Publisher:
Wiley
Publication Date:
1992
detail.hit.zdb_id:
1460391-3
SSG:
12
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