Myeloma light chains are ligands for cubilin (gp280).

Published

Journal Article

Although myeloma light chains are known to undergo receptor-mediated endocytosis in the kidney, the molecular identity of the receptor has not been characterized. We examined the interaction between cubilin (gp280) and four species of light chains isolated from the urine of patients with multiple myeloma. Four lines of evidence identify cubilin, a giant glycoprotein receptor, which is restricted in distribution to endocytic scavenger pathways and which has potent effects on endosomal trafficking, as a potentially physiologically relevant binding site for light chains: 1) light chains coeluted during immunoaffinity purification of cubilin; 2) polyclonal antisera to cubilin but not control sera, displaced human light chain binding from rat renal brush-border membranes; 3) cubilin bound to multiple species of light chains during surface plasmon resonance; 4) anti-cubilin antiserum interfered with light chain endocytosis by visceral yolk sac epithelial cells. However, both binding of light chains to brush-border membranes and endocytosis of light chains by yolk sac epithelial cells were only partially inhibited by anticubilin antibodies, suggesting presence of additional or alternate binding sites for light chains. Excess light chain had a potent inhibitory effect on endosomal fusion in vitro. Binding showed dose and time-dependent saturability with low-affinity, high-capacity equilibrium binding parameters. These data demonstrate that cubilin plays a role in the endocytosis and trafficking of light chains in renal proximal tubule cells.

Full Text

Duke Authors

Cited Authors

  • Batuman, V; Verroust, PJ; Navar, GL; Kaysen, JH; Goda, FO; Campbell, WC; Simon, E; Pontillon, F; Lyles, M; Bruno, J; Hammond, TG

Published Date

  • August 1998

Published In

Volume / Issue

  • 275 / 2

Start / End Page

  • F246 - F254

PubMed ID

  • 9691015

Pubmed Central ID

  • 9691015

International Standard Serial Number (ISSN)

  • 0002-9513

Digital Object Identifier (DOI)

  • 10.1152/ajprenal.1998.275.2.F246

Language

  • eng

Conference Location

  • United States