Plasminogen structural domains exhibit different functions when associated with cell surface GRP78 or the voltage-dependent anion channel.

Published

Journal Article

Both the voltage-dependent anion channel and the glucose-regulated protein 78 have been identified as plasminogen kringle 5 receptors on endothelial cells. In this study, we demonstrate that kringle 5 binds to a region localized in the N-terminal domain of the glucose-regulated protein 78, whereas microplasminogen does so through the C-terminal domain of the glucose-regulated protein 78. Both plasminogen fragments induce Ca(2+) signaling cascades; however, kringle 5 acts through voltage-dependent anion channel and microplasminogen does so via the glucose-regulated protein 78. Because trafficking of voltage-dependent anion channel to the cell surface is associated with heat shock proteins, we investigated a possible association between voltage-dependent anion channel and glucose-regulated protein 78 on the surface of 1-LN human prostate tumor cells. We demonstrate that these proteins co-localize, and changes in the expression of the glucoseregulated protein 78 affect the expression of voltage-dependent anion channel. To differentiate the functions of these receptor proteins, either when acting singly or as a complex, we employed human hexokinase I as a specific ligand for voltage-dependent anion channel, in addition to kringle 5. We show that kringle 5 inhibits 1-LN cell proliferation and promotes caspase-7 activity by a mechanism that requires binding to cell surface voltage-dependent anion channel and is inhibited by human hexokinase I.

Full Text

Duke Authors

Cited Authors

  • Gonzalez-Gronow, M; Kaczowka, SJ; Payne, S; Wang, F; Gawdi, G; Pizzo, SV

Published Date

  • November 9, 2007

Published In

Volume / Issue

  • 282 / 45

Start / End Page

  • 32811 - 32820

PubMed ID

  • 17848573

Pubmed Central ID

  • 17848573

International Standard Serial Number (ISSN)

  • 0021-9258

Digital Object Identifier (DOI)

  • 10.1074/jbc.M703342200

Language

  • eng

Conference Location

  • United States