c-Jun activating binding protein 1 binds to the IgA receptor and modulates protein levels of FcalphaRI and FcRgamma-chain.
The receptor for IgA, FcalphaRI or CD89, is expressed on myeloid cells and can trigger phagocytosis, tumor cell lysis, and release of inflammatory mediators. These functions critically depend on the associated FcR gamma-chain; however, some biological functions, like receptor internalization, are solely mediated by FcalphaRI alpha-chain. Little is known as to how FcalphaRI regulates these processes and the FcalphaRI intracellular domain does not contain recognized signalling motifs. We searched for associating proteins and identified c-Jun activating binding protein 1 (JAB1) as a binding partner specifically for FcalphaRI. We found increased FcalphaRI surface expression after ectopic expression of JAB1 as well as diminished protein levels of total FcR gamma-chain levels after JAB1 knock-down. These data functionally link JAB1 with controlling protein expression levels of FcalphaRI-FcR gamma-chain protein complex.
Bakema
Jantine E
JE
The Immunotherapy laboratory, Department of Immunology, University Medical Center Utrecht, Utrecht, The Netherlands.
Hiemstra
Ida H
IH
Bakker
Johanna
J
de Haij
Simone
S
Kok
Yvonne
Y
Adema
Gosse
G
van Egmond
Marjolein
M
Coffer
Paul J
PJ
van de Winkel
Jan G J
JG
Leusen
Jeanette H W
JH
D020816:Amino Acid Motifs / Q000235:genetics; D000818:Animals; D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism*; D000075686:COP9 Signalosome Complex; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D051379:Mice; D041681:NIH 3T3 Cells; D010447:Peptide Hydrolases / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D011485:Protein Binding / Q000235:genetics; D054730:Protein Interaction Domains and Motifs / Q000235:genetics; D055550:Protein Stability; D034741:RNA, Small Interfering / Q000235:genetics; D011961:Receptors, Fc / Q000235:genetics / Q000378:metabolism*; D017452:Receptors, IgG / Q000096:biosynthesis* / Q000235:genetics; D015533:Transcriptional Activation / Q000235:genetics; D019076:Transgenes / Q000235:genetics; D020298:U937 Cells
D015703:Antigens, CD; C036832:Fc(alpha) receptor; D047908:Intracellular Signaling Peptides and Proteins; D034741:RNA, Small Interfering; D011961:Receptors, Fc; D017452:Receptors, IgG; D010447:Peptide Hydrolases; C501488:COPS5 protein, human; D000075686:COP9 Signalosome Complex