Citation
- Authors: Lu F. et al.
- Year: 2022
- Journal: Nat Commun 13 2362
- Applications: in vitro / DNA / jetOPTIMUS
- Cell types:
- Name: CHO
Description: Chinese hamster ovary cells - Name: MEF
Description: Murine embryonic fibroblast cells
- Name: CHO
Method
In the case of protein knockdown, cells were pretreated with siRNA purchased from Sigma (universal negative control#1 (NC, Catalog#SIC001)) or siRNA duplexes (Catalog#VC30002) specifically designed for CHO cells: pxn_s02 CACUUUGUCUGCACCCACUdTdT; K2_s01 GAACUUGCUGACUAUAUUAdTdT; TLN_s03 CAGCAAUUGACAGGACACUCAdTdT for 48 h and then transfected with jetOPTIMUS (Polyplus).
Mouse embryonic fibroblast (MEF) cell line (ATCC#CRL-1503) and the MEF-derived Kindlin-2-knockout cell line (clone1–3, kindly provided by Dr. Huan Liu56) were maintained in the DMEM supplemented with 10% fetal bovine serum. Cells were transfected with siRNA for knockdown and followed with jetOPTIMUS (Polyplus) for mCherry-tagged proteins.
Abstract
Talin-induced integrin binding to extracellular matrix ligands (integrin activation) is the key step to trigger many fundamental cellular processes including cell adhesion, cell migration, and spreading. Talin is widely known to use its N-terminal head domain (talin-H) to bind and activate integrin, but how talin-H operates in the context of full-length talin and its surrounding remains unknown. Here we show that while being capable of inducing integrin activation, talin-H alone exhibits unexpectedly low potency versus a constitutively activated full-length talin. We find that the large C-terminal rod domain of talin (talin-R), which otherwise masks the integrin binding site on talin-H in inactive talin, dramatically enhances the talin-H potency by dimerizing activated talin and bridging it to the integrin co-activator kindlin-2 via the adaptor protein paxillin. These data provide crucial insight into the mechanism of talin and its cooperation with kindlin to promote potent integrin activation, cell adhesion, and signaling.