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Dissecting the Role of ArhGAP12 in Natural Killer Cell‐Mediated Cytotoxicity
Author(s) -
Heyblom Raini A.,
Overlee Brittany L.,
Billadeau Daniel B.
Publication year - 2019
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2019.33.1_supplement.792.5
Subject(s) - nkg2d , microbiology and biotechnology , biology , innate immune system , natural killer cell , cdc42 , effector , cytotoxicity , actin cytoskeleton , immunological synapse , podosome , receptor , signal transduction , cell , immune system , cytoskeleton , immunology , t cell , t cell receptor , biochemistry , in vitro
The immune system consists of two broad branches: innate and adaptive. In the innate branch of the immune system, one will find natural killer (NK) cells, which are responsible for recognizing and killing virally infected or cancerous cells within the human body. Numerous immunodeficiency syndromes arise from mutations in genes that encode proteins essential to NK cells including those involved in NK cell development and effector functions. Among the most important NK cell effector functions is cell‐mediated cytotoxicity. Our lab has been interested in understanding the molecular machinery that regulates this process, in particular those regulated by the small GTP‐binding proteins of the Rho family. With this in mind, the ArhGAP12 protein, which functions as a GTPase activating protein for members of the Rho family, was tested in NK cells to see if it had an effect on cytotoxicity. Significantly, knockdown of ArhGAP12 in NK cells resulted in diminished NK cell‐mediated cytotoxicity. In addition, we found that ArhGAP12 is tyrosine phosphorylated following stimulation through the NKG2D+2B4 activating receptors, indicating that it is linked to this important signaling pathway. As ArhGAP12 is a multi‐modular signaling protein containing a src‐homology 3 (SH3), WW, pleckstrin homology (PH), and GAP domains, we performed proteomics to identify potential interacting partners using the SH3 domain as bait. We found that ArhGAP12 interacts strongly with multiple regulators of F‐actin dynamics including WAVE2, WASP, Evl and VASP. Taken together, these results suggest that ArhGAP12 is linked to activating receptors on NK cells, associates with F‐actin regulators, and is involved in NK cell‐mediated cytotoxicity. Support or Funding Information Mayo Clinic Graduate School of Biomedical Sciences SURF Program and the R01 grant AI120949 to D.D.B. This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .