Association of RACK1 and PKCbeta with the common beta-chain of the IL-5/IL-3/GM-CSF receptor.
Granulocyte macrophage colony stimulating factor (GM-CSF), interleukin-3 (IL-3) and interleukin-5 (IL-5 belong to a family of cytokines that regulate proliferation, differentiation and function of haematopoietic cells. Their receptor consists of a ligand specific alpha-chain and a signal transducing beta-chain (betac). While, the role of phosphotyrosine residues in the betac as mediators of downstream signalling cascades has been established, little is known about non-phosphotyrosine mediated events. To identify proteins interacting with betac, we screened a yeast two-hybrid library with the intracellular domain of betac. We found that RACK1, a molecule associating with activated PKC, PLCgamma and Src kinases, associated with the membrane proximal region of betac in both yeast two-hybrid, immunoprecipitation and GST-pull-down assays. The association of RACK1 was constitutive, demonstrating no alteration upon cellular stimulation. Furthermore, upon stimulation of cells with IL-5 or PMA, a complex of betac and PKCbeta was found. Together, these findings suggest a novel role for RACK1 as a possible adapter molecule associating with the intracellular domain of cytokine receptors.
Geijsen
N
N
Department of Pulmonary Diseases, University Hospital Utrecht, Heidelberglaan 100, 3508 GA Utrecht, The Netherlands.
Spaargaren
M
M
Raaijmakers
J A
JA
Lammers
J W
JW
Koenderman
L
L
Coffer
P J
PJ
D000818:Animals; D001483:Base Sequence; D019556:COS Cells; D004247:DNA; D007527:Isoenzymes / Q000378:metabolism*; D010455:Peptides / Q000378:metabolism*; D011485:Protein Binding; D011493:Protein Kinase C / Q000378:metabolism*; D064546:Protein Kinase C beta; D000075370:Receptors for Activated C Kinase; D016187:Receptors, Granulocyte-Macrophage Colony-Stimulating Factor / Q000378:metabolism*; D018123:Receptors, Interleukin / Q000378:metabolism*; D016185:Receptors, Interleukin-3 / Q000378:metabolism*; D053649:Receptors, Interleukin-5
D007527:Isoenzymes; D010455:Peptides; D000075370:Receptors for Activated C Kinase; D016187:Receptors, Granulocyte-Macrophage Colony-Stimulating Factor; D018123:Receptors, Interleukin; D016185:Receptors, Interleukin-3; D053649:Receptors, Interleukin-5; C070301:peptide I; D004247:DNA; D011493:Protein Kinase C; D064546:Protein Kinase C beta