The structural basis of the Talin-KANK1 interaction that coordinates the actin and microtubule cytoskeletons at focal adhesions



Li, X, Goult, BT ORCID: 0000-0002-3438-2807, Ballestrem, C ORCID: 0000-0002-5375-7985 and Zacharchenko, T ORCID: 0000-0001-5621-8605
(2023) The structural basis of the Talin-KANK1 interaction that coordinates the actin and microtubule cytoskeletons at focal adhesions. [Preprint]

Access the full-text of this item by clicking on the Open Access link.

Abstract

Adhesion between cells and the extracellular matrix (ECM) is mediated by heterodimeric (αβ) integrin receptors that are intracellularly linked to the contractile actomyosin machinery. One of the proteins that control this link is talin, which organises cytosolic signalling proteins into discrete complexes on β-integrin tails referred to as focal adhesions (FAs). The adapter protein KANK1 binds to talin in the region of FAs known as the adhesion belt. Here, we developed a novel crystallographic method to resolve the talin-KANK1 complex. This structure revealed that the talin binding KN motif of KANK1 has a novel fold, where a β-turn stabilises the α-helical region, explaining its specific interaction with talin R7 and high affinity. Single point mutants in KANK1 identified from the structure abolished the interaction and enabled us to examine KANK1 enrichment in the adhesion belt. Strikingly, in cells expressing a constitutively active form of vinculin that keeps the FA structure intact even in the presence of myosin inhibitors, KANK1 localises throughout the entire FA structure even when actomyosin tension is released. We propose a model whereby actomyosin forces on talin eliminate KANK1 from talin binding in the centre of FAs while retaining it at the adhesion periphery.

Item Type: Preprint
Uncontrolled Keywords: 1.1 Normal biological development and functioning, 1 Underpinning research, Generic health relevance
Divisions: Faculty of Health and Life Sciences
Faculty of Health and Life Sciences > Institute of Systems, Molecular and Integrative Biology
Depositing User: Symplectic Admin
Date Deposited: 13 Mar 2024 10:02
Last Modified: 15 Mar 2024 20:50
DOI: 10.1101/2023.02.23.529676
Open Access URL: https://doi.org/10.1101/2023.02.23.529676
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3179301