CD44 is the signaling component of the macrophage migration inhibitory factor-CD74 receptor complex.

Published

Journal Article

The macrophage migration inhibitory factor (MIF) receptor (CD74) was cloned recently, but the signaling mechanism is not evident. We hypothesized that signaling requires an additional molecule such as CD44, which activates nonreceptor tyrosine kinases. We utilized the CD74- and CD44-deficient COS-7/M6 cell to create stable transfectants expressing CD74, CD44, and a truncated CD44 lacking its intracytoplasmic signaling domain. CD74 alone mediated MIF binding; however, MIF-induced ERK1 and ERK2 kinase phosphorylation required the coexpression of full-length CD44. MIF binding was associated with the serine phosphorylation of CD74 and CD44. Investigations that used siRNA or kinase inhibitors indicate that MIF-induced ERK1 and ERK2 activation through CD44 required the Src tyrosine kinase. Studies of CD74, CD44, and CD74-CD44 transformants and corresponding mutant cells showed that CD74 and CD44 were necessary for MIF protection from apoptosis. These data establish CD44 as an integral member of the CD74 receptor complex leading to MIF signal transduction.

Full Text

Cited Authors

  • Shi, X; Leng, L; Wang, T; Wang, W; Du, X; Li, J; McDonald, C; Chen, Z; Murphy, JW; Lolis, E; Noble, P; Knudson, W; Bucala, R

Published Date

  • October 2006

Published In

Volume / Issue

  • 25 / 4

Start / End Page

  • 595 - 606

PubMed ID

  • 17045821

Pubmed Central ID

  • 17045821

Electronic International Standard Serial Number (EISSN)

  • 1097-4180

International Standard Serial Number (ISSN)

  • 1074-7613

Digital Object Identifier (DOI)

  • 10.1016/j.immuni.2006.08.020

Language

  • eng