Structure and function of the N-terminal extension of the formin INF2
EntityUAM. Departamento de Biología Molecular
10.1007/s00018-022-04581-yCellular and Molecular Life Sciences 79.11 (2022): 571
ISSN1420-682X (print); 1420-9071 (online)
SubjectsCalcium Ion; Protein MRTF; Rho Factor; Methenamine; Actin; Biología y Biomedicina / Biología
Rights© The Author(s) 2022
Esta obra está bajo una Licencia Creative Commons Atribución 4.0 Internacional.
In INF2—a formin linked to inherited renal and neurological disease in humans—the DID is preceded by a short N-terminal extension of unknown structure and function. INF2 activation is achieved by Ca2+-dependent association of calmodulin (CaM). Here, we show that the N-terminal extension of INF2 is organized into two α-helices, the first of which is necessary to maintain the perinuclear F-actin ring and normal cytosolic F-actin content. Biochemical assays indicated that this helix interacts directly with CaM and contains the sole CaM-binding site (CaMBS) detected in INF2. The residues W11, L14 and L18 of INF2, arranged as a 1-4-8 motif, were identified as the most important residues for the binding, W11 being the most critical of the three. This motif is conserved in vertebrate INF2 and in the human population. NMR and biochemical analyses revealed that CaM interacts directly through its C-terminal lobe with the INF2 CaMBS. Unlike control cells, INF2 KO cells lacked the perinuclear F-actin ring, had little cytosolic F-actin content, did not respond to increased Ca2+ concentrations by making more F-actin, and maintained the transcriptional cofactor MRTF predominantly in the cytoplasm. Whereas expression of intact INF2 restored all these defects, INF2 with inactivated CaMBS did not. Our study reveals the structure of the N-terminal extension, its interaction with Ca2+/CaM, and its function in INF2 activation
Google Scholar:Labat-de-Hoz, Leticia - Comas, Laura - Rubio-Ramos, Armando - Casares-Arias, Javier - Fernández‑Martín, Laura - Pantoja‑Uceda, David - Martín, M. Teresa - Kremer, Leonor - Jiménez, M. Ángeles - Correas Hornero, María Isabel - Alonso, Miguel A.
This item appears in the following Collection(s)
Showing items related by title, author, creator and subject.
MALL, a membrane-tetra-spanning proteolipid overexpressed in cancer, is present in membraneless nuclear biomolecular condensates
A model for primary cilium biogenesis by polarized epithelial cells: role of the midbody remnant and associated specialized membranes
MYADM controls endothelial barrier function through ERM-dependent regulation of ICAM-1 expression