CIN85 Interacting Proteins in B Cells-Specific Role for SHIP-1

• Published in: Molecular & cellular proteomics Vol. 10; no. 10; p. M110.006239
• Main Authors: Büchse, Tom, Horras, Nikolaus, Lenfert, Eva, Krystal, Gerald, Körbel, Sandra, Schümann, Michael, Krause, Eberhard, Mikkat, Stefan, Tiedge, Markus
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-10-2011; The American Society for Biochemistry and Molecular Biology
• Subjects: Adaptor Proteins, Signal Transducing; Animals; B-Lymphocytes - metabolism; Binding Sites; Cell Line, Tumor; Gene Expression Regulation; Humans; Inositol Polyphosphate 5-Phosphatases; Jurkat Cells; Male; Mass Spectrometry; Mice; Mice, Inbred C57BL; Multiprotein Complexes - metabolism; Neoplasm Proteins - genetics; Neoplasm Proteins - metabolism; Nerve Tissue Proteins - genetics; Nerve Tissue Proteins - metabolism; Phosphatidylinositol 3-Kinase - metabolism; Phosphatidylinositol Phosphates - chemistry; Phosphatidylinositol Phosphates - metabolism; Phosphatidylinositol-3,4,5-Trisphosphate 5-Phosphatases; Phosphoric Monoester Hydrolases - genetics; Phosphoric Monoester Hydrolases - metabolism; Protein Binding; Proteomics; Proto-Oncogene Proteins c-cbl - metabolism; Recombinant Proteins - metabolism; Signal Transduction; Spleen - cytology; src Homology Domains
• ISSN: 1535-9476; 1535-9484
• DOI: 10.1074/mcp.M110.006239

The Cbl-interacting 85-kDa protein (CIN85) plays an important role as a negative regulator of signaling pathways induced by receptor tyrosine kinases. By assembling multiprotein complexes this versatile adaptor enhances receptor tyrosine kinase-activated clathrin-mediated endocytosis and reduces phosphatidylinositol-3-kinase-induced phosphatidylinositol-3,4,5-trisphosphate production. Here we report the expression of CIN85 in primary splenic B lymphocytes and the B-lymphoma cell lines WEHI 231 and Ba/F3. Cross-linking of the B cell antigen receptor resulted in an increased association of CIN85 with the ubiquitin ligase Cbl. Through a systematic pull-down proteomics approach we identified 51 proteins that interact with CIN85 in B cells, including proteins not shown previously to be CIN85-associated. Among these proteins, the SH2-containing inositol phosphatase 1 (SHIP-1) co-precipitated with both the full-length CIN85 and each of its three SH3 domains. We also showed that this association is constitutive and depends on a region of 79 amino acids near the carboxyl terminus of SHIP-1, a region rich in potential SH3 domain binding sites. Because SHIP-1 is a major negative regulator of the phosphatidylinositol-3-kinase pathway in lymphocytes, we hypothesize that the interaction between SHIP-1 and CIN85 might synergistically facilitate the down-regulation of phosphatidylinositol-3,4,5-trisphosphate levels.