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Merő B, Koprivanacz K, Cserkaszky A, Radnai L, Vas V, Kudlik G, Gógl G, Sok P, Póti ÁL, Szeder B, Nyitray L, Reményi A, Geiszt M, Buday L. Characterization of the Intramolecular Interactions and Regulatory Mechanisms of the Scaffold Protein Tks4. Int J Mol Sci 2021; 22:ijms22158103. [PMID: 34360869 PMCID: PMC8348221 DOI: 10.3390/ijms22158103] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 07/19/2021] [Accepted: 07/26/2021] [Indexed: 01/01/2023] Open
Abstract
The scaffold protein Tks4 is a member of the p47phox-related organizer superfamily. It plays a key role in cell motility by being essential for the formation of podosomes and invadopodia. In addition, Tks4 is involved in the epidermal growth factor (EGF) signaling pathway, in which EGF induces the translocation of Tks4 from the cytoplasm to the plasma membrane. The evolutionarily-related protein p47phox and Tks4 share many similarities in their N-terminal region: a phosphoinositide-binding PX domain is followed by two SH3 domains (so called “tandem SH3”) and a proline-rich region (PRR). In p47phox, the PRR is followed by a relatively short, disordered C-terminal tail region containing multiple phosphorylation sites. These play a key role in the regulation of the protein. In Tks4, the PRR is followed by a third and a fourth SH3 domain connected by a long (~420 residues) unstructured region. In p47phox, the tandem SH3 domain binds the PRR while the first SH3 domain interacts with the PX domain, thereby preventing its binding to the membrane. Based on the conserved structural features of p47phox and Tks4 and the fact that an intramolecular interaction between the third SH3 and the PX domains of Tks4 has already been reported, we hypothesized that Tks4 is similarly regulated by autoinhibition. In this study, we showed, via fluorescence-based titrations, MST, ITC, and SAXS measurements, that the tandem SH3 domain of Tks4 binds the PRR and that the PX domain interacts with the third SH3 domain. We also investigated a phosphomimicking Thr-to-Glu point mutation in the PRR as a possible regulator of intramolecular interactions. Phosphatidylinositol-3-phosphate (PtdIns(3)P) was identified as the main binding partner of the PX domain via lipid-binding assays. In truncated Tks4 fragments, the presence of the tandem SH3, together with the PRR, reduced PtdIns(3)P binding, while the presence of the third SH3 domain led to complete inhibition.
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Affiliation(s)
- Balázs Merő
- Research Centre for Natural Sciences, Institute of Enzymology, 1117 Budapest, Hungary; (B.M.); (K.K.); (A.C.); (L.R.); (V.V.); (G.K.); (B.S.)
| | - Kitti Koprivanacz
- Research Centre for Natural Sciences, Institute of Enzymology, 1117 Budapest, Hungary; (B.M.); (K.K.); (A.C.); (L.R.); (V.V.); (G.K.); (B.S.)
| | - Anna Cserkaszky
- Research Centre for Natural Sciences, Institute of Enzymology, 1117 Budapest, Hungary; (B.M.); (K.K.); (A.C.); (L.R.); (V.V.); (G.K.); (B.S.)
| | - László Radnai
- Research Centre for Natural Sciences, Institute of Enzymology, 1117 Budapest, Hungary; (B.M.); (K.K.); (A.C.); (L.R.); (V.V.); (G.K.); (B.S.)
| | - Virag Vas
- Research Centre for Natural Sciences, Institute of Enzymology, 1117 Budapest, Hungary; (B.M.); (K.K.); (A.C.); (L.R.); (V.V.); (G.K.); (B.S.)
| | - Gyöngyi Kudlik
- Research Centre for Natural Sciences, Institute of Enzymology, 1117 Budapest, Hungary; (B.M.); (K.K.); (A.C.); (L.R.); (V.V.); (G.K.); (B.S.)
| | - Gergő Gógl
- Department of Biochemistry, Eötvös Loránd University, 1117 Budapest, Hungary; (G.G.); (L.N.)
| | - Péter Sok
- Research Centre for Natural Sciences, Institute of Organic Chemistry, 1117 Budapest, Hungary; (P.S.); (Á.L.P.); (A.R.)
| | - Ádám L. Póti
- Research Centre for Natural Sciences, Institute of Organic Chemistry, 1117 Budapest, Hungary; (P.S.); (Á.L.P.); (A.R.)
| | - Bálint Szeder
- Research Centre for Natural Sciences, Institute of Enzymology, 1117 Budapest, Hungary; (B.M.); (K.K.); (A.C.); (L.R.); (V.V.); (G.K.); (B.S.)
| | - László Nyitray
- Department of Biochemistry, Eötvös Loránd University, 1117 Budapest, Hungary; (G.G.); (L.N.)
| | - Attila Reményi
- Research Centre for Natural Sciences, Institute of Organic Chemistry, 1117 Budapest, Hungary; (P.S.); (Á.L.P.); (A.R.)
| | - Miklós Geiszt
- Department of Physiology, Semmelweis University, 1094 Budapest, Hungary;
| | - László Buday
- Department of Biochemistry, Eötvös Loránd University, 1117 Budapest, Hungary; (G.G.); (L.N.)
- Department of Molecular Biology, Semmelweis University Medical School, 1094 Budapest, Hungary
- Correspondence:
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