Maps_Modules
HMC:ACTIVATING_INVASION_AND_METASTASIS
 EMT Senescence   / EMT_REGULATORS 
 EMT Senescence   / ECM 

References
PMID:21900405
Integrin aVb6 activates the ECM-bound latent TGFB1 and TGFB3 by traction, without participation of MMPs, so no hydrolyse or clevage
Integrin aVb8 and MMP14 (so-called MT1-MMP) cooperate to activate the ECM-bound latent TGFB1 and TGFB3:
-Integrin aVb8 binds LAP from the large latent complex
-MMP14 then is recruited to cleave LAP
PMID:18342983
Two main models are proposed how integrins contribute to latent TGFB1 activation:
(1) In a protease-dependent mechanism, integrins avb8and avb3 are suggested to simultaneously bind the latent TGFB1 complex and proteinases.
This close vicinity at the cell surface improves enzymatic cleavage of the latent complex to release active TGFB1.
(2) Integrins avb3, avb5, avb6, and avb8 appear to change the conformation of the latent TGFB1 complex by transmitting cell traction forces.
PMID:19854168
Integrins are linked intracellularly to cytoskleletal elements and associated contractile machinery, and extracellularly to ECM.
Thus contractility of a cell bound to a rigid ECM generates force between a matrix molecule and its receptor. Such forces may uncouple LLCs so as to free TGFb.
PMID:16710477
The small GTPase RhoA has well established roles in contractility and has been shown to promote TGFb activation from LLCs.