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Updated: May 19, 2026

In Vivo Detection and Analysis of Rb Protein SUMOylation in Human Cells
Published on: November 2, 2017
Post-translational modification of the RhoGTPase activating protein 21, ARHGAP21, by SUMO2/3
Carolina L Bigarella1, Karla P Vieira Ferro, Karin S A Barcellos
1Hematology and Hemotherapy Center, University of Campinas, Campinas, São Paulo, Brazil.
Abstract:
ARHGAP21 is a 217 kDa RhoGAP protein shown to modulate cell migration through the control of Cdc42 and FAK activities. In the present work a 250 kDa-ARHGAP21 was identified by mass spectrometry. This modified form is differentially expressed among cell lines and human primary cells. Co-immunoprecipitations and in vitro SUMOylation confirmed ARHGAP21 specific modification by SUMO2/3 and mapped the SUMOylation site to ARHGAP21 lysine K1443. Immunofluorescence staining revealed that ARHGAP21 co-localizes with SUMO2/3 in the cytoplasm and membrane compartments. Interestingly, our results suggest that ARHGAP21 SUMOylation may be related to cell proliferation. Therefore, SUMOylation of ARHGAP21 may represent a way of guiding its function.
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