scholarly journals MT1-MMP hemopexin domain exchange with MT4-MMP blocks enzyme maturation and trafficking to the plasma membrane in MCF7 cells

2006 ◽  
Vol 398 (1) ◽  
pp. 15-22 ◽  
Author(s):  
Susan J. Atkinson ◽  
Christian Roghi ◽  
Gillian Murphy

The hemopexin-like domain of membrane-type matrix metalloproteinase-1 (MT1-MMP) enables MT1-MMP to form oligomers that facilitate the activation of pro-matrix metalloproteinase-2 (pro-MMP-2) at the cell surface. To investigate the role of the MT1-MMP hemopexin domain in the trafficking of MT1-MMP to the cell surface we have examined the activity of two MT1–MT4-MMP chimaeras in which the hemopexin domain of MT1-MMP has been replaced with that of human or mouse MT4-MMP. We show that MT1-MMP bearing the hemopexin domain of MT4-MMP was incapable of activating pro-MMP-2 or degrading gelatin in cell based assays. Furthermore, cell surface biotinylation and indirect immunofluorescence show that transiently expressed MT1–MT4-MMP chimaeras failed to reach the plasma membrane and were retained in the endoplasmic reticulum. Functional activity could be restored by replacing the MT4-MMP hemopexin domain with the wild-type MT1-MMP hemopexin domain. Subsequent analysis with an antibody specifically recognising the propeptide of MT1-MMP revealed that the propeptides of the MT1–MT4-MMP chimaeras failed to undergo proper processing. It has previously been suggested that the hemopexin domain of MT4-MMP could exert a regulatory mechanism that prevents MT4-MMP from activating pro-MMP-2. In this report, we demonstrate unambiguously that MT1–MT4-MMP chimaeras do not undergo normal trafficking and are not correctly processed to their fully active forms and, as a consequence, they are unable to activate pro-MMP-2 at the cell surface.

2019 ◽  
Vol 316 (1) ◽  
pp. C92-C103 ◽  
Author(s):  
Hojin Kang ◽  
Zhigang Hong ◽  
Ming Zhong ◽  
Jennifer Klomp ◽  
Kayla J. Bayless ◽  
...  

Angiogenesis is initiated in response to a variety of external cues, including mechanical and biochemical stimuli; however, the underlying signaling mechanisms remain unclear. Here, we investigated the proangiogenic role of the endothelial mechanosensor Piezo1. Genetic deletion and pharmacological inhibition of Piezo1 reduced endothelial sprouting and lumen formation induced by wall shear stress and proangiogenic mediator sphingosine 1-phosphate, whereas Piezo1 activation by selective Piezo1 activator Yoda1 enhanced sprouting angiogenesis. Similarly to wall shear stress, sphingosine 1-phosphate functioned by activating the Ca2+ gating function of Piezo1, which in turn signaled the activation of the matrix metalloproteinase-2 and membrane type 1 matrix metalloproteinase during sprouting angiogenesis. Studies in mice in which Piezo1 was conditionally deleted in endothelial cells demonstrated the requisite role of sphingosine 1-phosphate-dependent activation of Piezo1 in mediating angiogenesis in vivo. These results taken together suggest that both mechanical and biochemical stimuli trigger Piezo1-mediated Ca2+ influx and thereby activate matrix metalloproteinase-2 and membrane type 1 matrix metalloproteinase and synergistically facilitate sprouting angiogenesis.


2000 ◽  
Vol 345 (3) ◽  
pp. 511-519 ◽  
Author(s):  
Yihyung JO ◽  
Jungheum YEON ◽  
Hwa-Jung KIM ◽  
Seung-Taek LEE

Membrane-type 1 matrix metalloproteinase (MT1-MMP; MMP14) is known to activate pro-matrix metalloproteinase-2 (pro-MMP-2; progelatinase A) on the cell surface. To analyse the tissue inhibitor of metalloproteinases-2 (TIMP-2) effect on activation of pro-MMP-2 by MT1-MMP, we have expressed the full-size MT1-MMP (fMT1-MMP) and a transmembrane (TM)-domain-deleted soluble MT1-MMP (sMT1-MMP) in the baculovirus/Sf9 (Spodoptera frugiperda 9) insect-cell system, where neither endogenous gelatinolytic MMPs nor TIMP-2 are expressed. Both fMT1-MMP and sMT1-MMP expressed in the expression system were found not to contain the pro-domain and were able to activate the TIMP-2-free pro-MMP-2. Both in the insect cells and in vitro, activation of pro-MMP-2 by fMT1-MMP was enhanced at low concentrations of TIMP-2 and inhibited by its higher concentrations. The maximal enhancing effect was detected at 0.05 molar fraction of TIMP-2/fMT1-MMP. In contrast, activation of pro-MMP-2 by sMT1-MMP was dose-dependently inhibited by TIMP-2. These results demonstrate that the TM domain of MT1-MMP is not required for the ability to activate pro-MMP-2, but is required for the enhancing effect of TIMP-2 on pro-MMP-2 activation by recruiting pro-MMP-2 to the MT1-MMP-TIMP-2 complex as a cell-surface pro-MMP-2 receptor. Moreover, our data strongly suggest that the pro-domain of MT1-MMP is not required for the TIMP-2-mediated enhancing effect on pro-MMP-2 activation. In addition, the pro-MMP-2 in the MT1-MMP-TIMP-2-pro-MMP-2 ternary complex was not activated without external activator, but readily by addition of sMT1-MMP. This result demonstrates that MT1-MMP free of TIMP-2 would be the enzyme responsible for activation of the pro-MMP-2 in the ternary complex under physiological conditions.


2001 ◽  
Vol 276 (50) ◽  
pp. 47402-47410 ◽  
Author(s):  
Charlotte J. Morrison ◽  
Georgina S. Butler ◽  
Heather F. Bigg ◽  
Clive R. Roberts ◽  
Paul D. Soloway ◽  
...  

The role of membrane-type (MT) 2-matrix metalloproteinase (MMP) in the cellular activation of MMP-2 and the tissue inhibitor of matrix metalloproteinase (TIMP) requirements for this process have not been clearly established. To address these issues a TIMP-2-free cell line derived from aTimp2−/− mouse was transfected for stable cell surface expression of hMT2-MMP. Untransfected cells did not activate endogenous or exogenous TIMP-2-free MMP-2 unless both TIMP-2 and concanavalin A (ConA) were added. Transfected cells expressing hMT2-MMP efficiently activated both endogenous and exogenous MMP-2 (within 4 h) via the 68-kDa intermediate in the absence of TIMP-2 and ConA. In contrast, activation of MMP-2 byTimp2−/− cells expressing recombinant hMT1-MMP occurred more slowly (12 h) and required the addition of 0.3–27 nmTIMP-2. Addition of TIMP-2 or TIMP-4 did not enhance MMP-2 activation by MT2-MMP at any concentration tested; furthermore, activation was inhibited by both TIMPs at concentrations >9 nm, consistent with the similar association rate constants (kon) calculated for the binding of TIMP-4 and TIMP-2 to MT2-MMP (3.56 × 105m−1s−1and 6.52 × 105m−1s−1, respectively). MT2-MMP-mediated activation involved cell surface association of the MMP-2 in a hemopexin carboxyl-terminal domain (C domain)-dependent manner: Exogenous MMP-2 hemopexin C domain blocked activation, and cells expressing hMT2-MMP did not bind or activate a truncated form of MMP-2 lacking the hemopexin C domain. These studies demonstrate the existence of an alternative TIMP-2-independent pathway for MMP-2 activation involving MT2-MMP, which may be important in mediating MMP-2 activation in specific tissues or pathologies where MT2-MMP is expressed.


Sign in / Sign up

Export Citation Format

Share Document