Talin mechanosensitivity is modulated by a direct interaction with cyclin-dependent kinase-1

Abstract

Talin is a mechanosensitive component of adhesion complexes that directly couples integrins to the actin cytoskeleton. In response to force, talin undergoes switch-like behaviour of its multiple rod domains that modulate interactions with its binding partners. Cyclin-dependent kinase-1 (CDK1) is a key regulator of the cell cycle, exerting its effects through synchronised phosphorylation of a large number of protein targets. CDK1 activity also maintains adhesion during interphase, and its inhibition is a prerequisite for the tightly choreographed changes in cell shape and adhesiveness that are required for successful completion of mitosis. Using a combination of biochemical, structural and cell biological approaches, we demonstrate a direct interaction between talin and CDK1 that occurs at sites of integrin- mediated adhesion. Mutagenesis demonstrated that CDK1 contains a functional talin-binding LD motif, and the binding site within talin was pinpointed to helical bundle R8 through the use of recombinant fragments. Talin also contains a consensus CDK1 phosphorylation motif centred on S1589; a site that was phosphorylated by CDK1 in vitro. A phosphomimetic mutant of this site within talin lowered the binding affinity of KANK and weakened the mechanical response of the region, potentially altering downstream mechanotransduction pathways. The direct binding of the master cell cycle regulator, CDK1, to the primary integrin effector, talin, therefore provides a primordial solution for coupling the cell proliferation and cell adhesion machineries, and thereby enables microenvironmental control of cell division in multicellular organisms.

Talin rod domain–containing protein 1 (TLNRD1) is a novel actin-bundling protein which promotes filopodia formation

“…S2, I and J ). In contrast, multiple structures of talin1 R7R8 solved alone ( Gingras et al, 2010 ) and in complex ( Chang et al, 2014 ; Zacharchenko et al, 2016 ; Gough et al, 2021 ) show no equivalent interactions between R7 and R8. Thus, it is possible that this more compact conformation might represent an autoinhibited conformation of TLNRD1, rendering some binding sites cryptic.…”

“…Talin R7R8 also binds to multiple other ligands, many of which contain leucine-aspartate motifs (LD motifs; Alam et al, 2014 ). R8 binds (i) Rap1-GTP–interacting adaptor molecule (RIAM), implicated in recruitment of talin to the leading edge of cells ( Chang et al, 2014 ; Goult et al, 2013 ) and to filopodial protrusions ( Lagarrigue et al, 2015 ); (ii) deleted in liver cancer 1 (DLC1; Zacharchenko et al, 2016 ; Li et al, 2011 ); (iii) paxillin ( Zacharchenko et al, 2016 ); and (iv) cyclin-dependent kinase 1 (CDK1; Gough et al, 2021 ). R8 also contains a binding site for vinculin ( Gingras et al, 2010 ) and the intermediate filament protein α-synemin ( Sun et al, 2008 ).…”

A subpopulation of Talin 1 resides in the nucleus and regulates gene expression

“…To initiate the study on the subcellular localization of talin 1 (TLN1), we examined the gene ontology (GO) terms associated with 1304 TLN1-interacting proteins, that were identified in a recently published mass spectrometry screen (Gough et al , 2021) (Fig 1A, right panel). Gough and collaborators determined the probability of bona fide protein-protein interactions by calculating the Significance Analysis of INTeractome (SAINT) score, and a total of 72 TLN1-interacting partners, which had a SAINT score ≥0.7, were chosen for our GO term analysis.…”

“…To initiate the study on the subcellular localization of talin 1 (TLN1), we examined the gene ontology (GO) terms associated with 1304 TLN1-interacting proteins, that were identified in a recently published mass spectrometry screen (Gough et al, 2021) (Fig 1A,right panel).…”

“…The fractionation controls were the same as in panel C and remanent signal from a previous LAM A/C immunoblot is indicated with an asterisk (*). Analysis of TLN1 interacting partners previously identified by Gough and collaborators (right panel) (Gough et al, 2021). Made in BioRender.com B) Gene ontology (GO) terms associated with TLN1 interacting partners were analyzed with the online application ShinyGO (Ge et al, 2020).…”