PKC-alpha-mediated remodeling of the actin cytoskeleton is involved in constitutive albumin uptake by proximal tubule cells

Hryciw, D, Pollock, C and Poronnik, P 2005, 'PKC-alpha-mediated remodeling of the actin cytoskeleton is involved in constitutive albumin uptake by proximal tubule cells', American Journal of Physiology: Renal Physiology, vol. 288, no. 6, pp. 1227-1235.


Document type: Journal Article
Collection: Journal Articles

Title PKC-alpha-mediated remodeling of the actin cytoskeleton is involved in constitutive albumin uptake by proximal tubule cells
Author(s) Hryciw, D
Pollock, C
Poronnik, P
Year 2005
Journal name American Journal of Physiology: Renal Physiology
Volume number 288
Issue number 6
Start page 1227
End page 1235
Total pages 9
Publisher American Physiological Society
Abstract One key role of the renal proximal tubule is the reabsorption of proteins from the glomerular filtrate by constitutive receptor-mediated endocytosis. In the opossum kidney (OK) renal proximal tubule cell line, inhibition of protein kinase C (PKC) reduces albumin uptake, although the isoforms involved and mechanisms by which this occurs have not been identified. We used pharmacological and molecular approaches to investigate the role of PKC-? in albumin endocytosis. We found that albumin uptake in OK cells was inhibited by the pan-PKC blocker bisindolylmaleimide-1 and the isoform-specific PKC blockers Gö 6976 and 2?,3,3?,4,4?-hexahydroxy-1,1?- biphenyl-6,6?-dimethanol dimethyl ether, indicating a role for PKC-?. Overexpression of a kinase deficient PKC-?(K368R) but not wild-type PKC-? significantly reduced albumin endocytosis. Western blot analysis of fractionated cells showed an increased association of PKC-?-green fluorescent protein with the membrane fraction within 10-20 min of exposure to albumin. We used phalloidin to demonstrate that albumin induces the formation of clusters of actin at the apical surface of OK cells and that these clusters correspond to the location of albumin uptake. These clusters were not present in cells grown in the absence of albumin. In cells treated either with PKC inhibitors or overexpressing kinase-deficient PKC-?(K368R) this actin cluster formation was significantly reduced. This study identifies a role for PKC-? in constitutive albumin uptake in OK cells by mediating assembly of actin microfilaments at the apical membrane.
Subject Cell Physiology
DOI - identifier 10.1152/ajprenal.00428.2003
Copyright notice Copyright © 2005 the American Physiological Society.
ISSN 1931-857X
Versions
Version Filter Type
Citation counts: Scopus Citation Count Cited 27 times in Scopus Article | Citations
Altmetric details:
Access Statistics: 39 Abstract Views  -  Detailed Statistics
Created: Mon, 06 Dec 2010, 14:11:00 EST by Catalyst Administrator
© 2014 RMIT Research Repository • Powered by Fez SoftwareContact us