SHIP2 (SH2 domain-containing inositol phosphatase 2) SH2 domain negatively controls SHIP2 monoubiquitination in response to epidermal growth factor.
The SH2 domain containing inositol 5-phosphatase SHIP2 contains several interacting domains that are important for scaffolding properties. We and others have previously reported that SHIP2 interacts with the E3 ubiquitin ligase c-Cbl. Here, we identified human SHIP2 monoubiquitination on lysine 315. SHIP2 could also be polyubiquitinated but was not degraded by the 26 S proteasome. Furthermore, we identified a ubiquitin-interacting motif at the C-terminal end of SHIP2 that confers ubiquitin binding capacity. However, this ubiquitin-interacting motif is dispensable for its monoubiquitination. We showed that neither c-Cbl nor Nedd4-1 play the role of ubiquitin ligase for SHIP2. Strikingly, monoubiquitination of the DeltaSH2-SHIP2 mutant (lacking the N-terminal SH2 domain) is strongly increased, suggesting an intrinsic inhibitory effect of the SHIP2 SH2 domain on its monoubiquitination. Moreover, SHIP2 monoubiquitination was increased upon 30 min of epidermal growth factor stimulation. This correlates with the loss of interaction between the SHIP2 SH2 domain and c-Cbl. In this model, c-Cbl could mask the monoubiquitination site and thereby prevent SHIP2 monoubiquitination. The present study thus reveals an unexpected and novel role of SHIP2 SH2 domain in the regulation of its newly identified monoubiquitination.
De Schutter
Julie
J
Institute of Interdisciplinary Research, School of Medicine, Free University of Brussels, Campus Erasme, Building C, Route de Lennik 808, B-1070 Brussels, Belgium.
Guillabert
Aude
A
Institute of Interdisciplinary Research, School of Medicine, Free University of Brussels, Campus Erasme, Building C, Route de Lennik 808, B-1070 Brussels, Belgium.
Imbault
Virginie
V
Institute of Interdisciplinary Research, School of Medicine, Free University of Brussels, Campus Erasme, Building C, Route de Lennik 808, B-1070 Brussels, Belgium.
Degraef
Chantal
C
Institute of Interdisciplinary Research, School of Medicine, Free University of Brussels, Campus Erasme, Building C, Route de Lennik 808, B-1070 Brussels, Belgium.
Erneux
Christophe
C
Institute of Interdisciplinary Research, School of Medicine, Free University of Brussels, Campus Erasme, Building C, Route de Lennik 808, B-1070 Brussels, Belgium.
Communi
David
D
Institute of Interdisciplinary Research, School of Medicine, Free University of Brussels, Campus Erasme, Building C, Route de Lennik 808, B-1070 Brussels, Belgium.
Pirson
Isabelle
I
Institute of Interdisciplinary Research, School of Medicine, Free University of Brussels, Campus Erasme, Building C, Route de Lennik 808, B-1070 Brussels, Belgium. Electronic address: ilpirson@ulb.ac.be.
D020816:Amino Acid Motifs / Q000502:physiology; D000818:Animals; D019556:COS Cells; D002522:Chlorocebus aethiops; D056827:Endosomal Sorting Complexes Required for Transport / Q000235:genetics / Q000378:metabolism; D004815:Epidermal Growth Factor / Q000378:metabolism* / Q000494:pharmacology; D006801:Humans; D008954:Models, Biological; D000075702:Nedd4 Ubiquitin Protein Ligases; D000072183:Phosphatidylinositol-3,4,5-Trisphosphate 5-Phosphatases; D010744:Phosphoric Monoester Hydrolases / Q000235:genetics / Q000378:metabolism*; D046988:Proteasome Endopeptidase Complex / Q000235:genetics / Q000378:metabolism; D017434:Protein Structure, Tertiary / Q000502:physiology; D050721:Proto-Oncogene Proteins c-cbl / Q000235:genetics / Q000378:metabolism; D013997:Time Factors; D044767:Ubiquitin-Protein Ligases / Q000235:genetics / Q000378:metabolism; D054875:Ubiquitination / Q000187:drug effects / Q000502:physiology*
D056827:Endosomal Sorting Complexes Required for Transport; D004815:Epidermal Growth Factor; D000075702:Nedd4 Ubiquitin Protein Ligases; C000618483:Nedd4 protein, human; D050721:Proto-Oncogene Proteins c-cbl; D044767:Ubiquitin-Protein Ligases; D010744:Phosphoric Monoester Hydrolases; C098706:INPPL1 protein, human; D000072183:Phosphatidylinositol-3,4,5-Trisphosphate 5-Phosphatases; D046988:Proteasome Endopeptidase Complex; C061553:ATP dependent 26S protease