start-ver=1.4 cd-journal=joma no-vol=11 cd-vols= no-issue=4 article-no= start-page=510 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2021 dt-pub=20210330 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Identification and Biochemical Characterization of High Mobility Group Protein 20A as a Novel Ca2+/S100A6 Target en-subtitle= kn-subtitle= en-abstract= kn-abstract=During screening of protein-protein interactions, using human protein arrays carrying 19,676 recombinant glutathione s-transferase (GST)-fused human proteins, we identified the high-mobility protein group 20A (HMG20A) as a novel S100A6 binding partner. We confirmed the Ca2+-dependent interaction of HMG20A with S100A6 by the protein array method, biotinylated S100A6 overlay, and GST-pulldown assay in vitro and in transfected COS-7 cells. Co-immunoprecipitation of S100A6 with HMG20A from HeLa cells in a Ca2+-dependent manner revealed the physiological relevance of the S100A6/HMG20A interaction. In addition, HMG20A has the ability to interact with S100A1, S100A2, and S100B in a Ca2+-dependent manner, but not with S100A4, A11, A12, and calmodulin. S100A6 binding experiments using various HMG20A mutants revealed that Ca2+/S100A6 interacts with the C-terminal region (residues 311-342) of HMG20A with stoichiometric binding (HMG20A:S100A6 dimer = 1:1). This was confirmed by the fact that a GST-HMG20A mutant lacking the S100A6 binding region (residues 311-347, HMG20A-Delta C) failed to interact with endogenous S100A6 in transfected COS-7 cells, unlike wild-type HMG20A. Taken together, these results identify, for the first time, HMG20A as a target of Ca2+/S100 proteins, and may suggest a novel linkage between Ca2+/S100 protein signaling and HMG20A function, including in the regulation of neural differentiation. en-copyright= kn-copyright= en-aut-name=YamamotoMaho en-aut-sei=Yamamoto en-aut-mei=Maho kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=KondoRina en-aut-sei=Kondo en-aut-mei=Rina kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=HozumiHaruka en-aut-sei=Hozumi en-aut-mei=Haruka kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=DoiSeita en-aut-sei=Doi en-aut-mei=Seita kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=DendaMiwako en-aut-sei=Denda en-aut-mei=Miwako kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=MagariMasaki en-aut-sei=Magari en-aut-mei=Masaki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=KanayamaNaoki en-aut-sei=Kanayama en-aut-mei=Naoki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=HatanoNaoya en-aut-sei=Hatano en-aut-mei=Naoya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= en-aut-name=MorishitaRyo en-aut-sei=Morishita en-aut-mei=Ryo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=9 ORCID= en-aut-name=TokumitsuHiroshi en-aut-sei=Tokumitsu en-aut-mei=Hiroshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=10 ORCID= affil-num=1 en-affil=Applied Cell Biology, Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University kn-affil= affil-num=2 en-affil=Applied Cell Biology, Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University kn-affil= affil-num=3 en-affil=Department of Applied Chemistry and Biotechnology, Faculty of Engineering, Okayama University kn-affil= affil-num=4 en-affil=Applied Cell Biology, Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University kn-affil= affil-num=5 en-affil=Cell Free Sciences Co., Ltd. kn-affil= affil-num=6 en-affil=Applied Cell Biology, Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University kn-affil= affil-num=7 en-affil=Applied Cell Biology, Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University kn-affil= affil-num=8 en-affil=Applied Cell Biology, Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University kn-affil= affil-num=9 en-affil=Cell Free Sciences Co., Ltd. kn-affil= affil-num=10 en-affil=Applied Cell Biology, Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University kn-affil= en-keyword=S100 protein kn-keyword=S100 protein en-keyword=HMG20A kn-keyword=HMG20A en-keyword=protein-protein interaction kn-keyword=protein-protein interaction en-keyword=Ca2+-signal transduction kn-keyword=Ca2+-signal transduction en-keyword=genome-wide screening kn-keyword=genome-wide screening END