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Evidence for a second alpha 2-macroglobulin receptor.

Publication ,  Journal Article
Misra, UK; Chu, CT; Gawdi, G; Pizzo, SV
Published in: J Biol Chem
April 29, 1994

alpha 2-Macroglobulin (alpha 2M)-methylamine binds to purified low density lipoprotein receptor-related protein (LRP), and it is assumed that LRP functions as the alpha 2M receptor in vivo. Binding of alpha 2M-methylamine to macrophage receptors elevates intracellular calcium ([Ca2+]i), inositol phosphates, and cyclic AMP. We have employed human alpha 2M-methylamine and recombinant receptor binding fragment (RBF) to study transduction mechanisms. Macrophages exposed to either ligand demonstrated a rapid rise in [Ca2+]i. Since the 39-kDa LRP/alpha 2M receptor-associated protein (RAP) blocks alpha 2M binding to LRP, we explored the effects of RAP upon signaling. Pretreatment of macrophages with RAP did not block the increase in [Ca2+]i elicited by alpha 2M-methylamine or RBF, suggesting a distinct binding site. RBF also elicited a transient 1.5-2.0-fold increase in inositol 1,4,5-triphosphate. In permeabilized macrophages, GTP gamma S and Gp-p(NH)p potentiated and sustained this inositol 1,4,5-triphosphate increase. Preincubation of permeabilized macrophages with GDP beta S abrogated the effects of GTP gamma S. Our results suggest that the signaling alpha 2M receptor is coupled to a pertussis toxin-insensitive G protein and possibly to a cholera toxin-sensitive G protein. We conclude that macrophages contain a second alpha 2M receptor that is G protein-coupled.

Duke Scholars

Published In

J Biol Chem

ISSN

0021-9258

Publication Date

April 29, 1994

Volume

269

Issue

17

Start / End Page

12541 / 12547

Location

United States

Related Subject Headings

  • alpha-Macroglobulins
  • Virulence Factors, Bordetella
  • Signal Transduction
  • Receptors, Immunologic
  • Proteins
  • Pertussis Toxin
  • Peptide Fragments
  • Mice, Inbred C57BL
  • Mice
  • Methylamines
 

Citation

APA
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MLA
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Misra, U. K., Chu, C. T., Gawdi, G., & Pizzo, S. V. (1994). Evidence for a second alpha 2-macroglobulin receptor. J Biol Chem, 269(17), 12541–12547.
Misra, U. K., C. T. Chu, G. Gawdi, and S. V. Pizzo. “Evidence for a second alpha 2-macroglobulin receptor.J Biol Chem 269, no. 17 (April 29, 1994): 12541–47.
Misra UK, Chu CT, Gawdi G, Pizzo SV. Evidence for a second alpha 2-macroglobulin receptor. J Biol Chem. 1994 Apr 29;269(17):12541–7.
Misra, U. K., et al. “Evidence for a second alpha 2-macroglobulin receptor.J Biol Chem, vol. 269, no. 17, Apr. 1994, pp. 12541–47.
Misra UK, Chu CT, Gawdi G, Pizzo SV. Evidence for a second alpha 2-macroglobulin receptor. J Biol Chem. 1994 Apr 29;269(17):12541–12547.

Published In

J Biol Chem

ISSN

0021-9258

Publication Date

April 29, 1994

Volume

269

Issue

17

Start / End Page

12541 / 12547

Location

United States

Related Subject Headings

  • alpha-Macroglobulins
  • Virulence Factors, Bordetella
  • Signal Transduction
  • Receptors, Immunologic
  • Proteins
  • Pertussis Toxin
  • Peptide Fragments
  • Mice, Inbred C57BL
  • Mice
  • Methylamines