In vivo gene transfer: prevention of neointima formation by inhibition of mitogen-activated protein kinase kinase

1997 ◽  
Vol 92 (6) ◽  
pp. 378-384 ◽  
Author(s):  
C. Indolfi ◽  
E. V. Avvedimento ◽  
A. Rapacciuolo ◽  
G. Esposito ◽  
E. Lorenzo ◽  
...  

1997 ◽  
Vol 92 (6) ◽  
pp. 378-384 ◽  
Author(s):  
C. Indolfi ◽  
E.V. Avvedimento ◽  
A. Rapacciuolo ◽  
G. Esposito ◽  
E. Di Lorenzo ◽  
...  


2000 ◽  
Vol 149 (2) ◽  
pp. 331-340 ◽  
Author(s):  
Antonino Colanzi ◽  
Thomas J. Deerinck ◽  
Mark H. Ellisman ◽  
Vivek Malhotra

Incubation of permeabilized cells with mitotic extracts results in extensive fragmentation of the pericentriolarly organized stacks of cisternae. The fragmented Golgi membranes are subsequently dispersed from the pericentriolar region. We have shown previously that this process requires the cytosolic protein mitogen-activated protein kinase kinase 1 (MEK1). Extracellular signal–regulated kinase (ERK) 1 and ERK2, the known downstream targets of MEK1, are not required for this fragmentation (Acharya et al. 1998). We now provide evidence that MEK1 is specifically phosphorylated during mitosis. The mitotically phosphorylated MEK1, upon partial proteolysis with trypsin, generates a different peptide population compared with interphase MEK1. MEK1 cleaved with the lethal factor of the anthrax toxin can still be activated by its upstream mitotic kinases, and this form is fully active in the Golgi fragmentation process. We believe that the mitotic phosphorylation induces a change in the conformation of MEK1 and that this form of MEK1 recognizes Golgi membranes as a target compartment. Immunoelectron microscopy analysis reveals that treatment of permeabilized normal rat kidney (NRK) cells with mitotic extracts, treated with or without lethal factor, converts stacks of pericentriolar Golgi membranes into smaller fragments composed predominantly of tubuloreticular elements. These fragments are similar in distribution, morphology, and size to the fragments observed in the prometaphase/metaphase stage of the cell cycle in vivo.



1994 ◽  
Vol 14 (3) ◽  
pp. 1594-1602
Author(s):  
A J Rossomando ◽  
P Dent ◽  
T W Sturgill ◽  
D R Marshak

Mitogen-activated protein kinase kinase 1 (MKK1), a dual-specificity tyrosine/threonine protein kinase, has been shown to be phosphorylated and activated by the raf oncogene product as part of the mitogen-activated protein kinase cascade. Here we report the phosphorylation and inactivation of MKK1 by phosphorylation on threonine 286 and threonine 292. MKK1 contains a consensus phosphorylation site for p34cdc2, a serine/threonine protein kinase that regulates the cell division cycle, at Thr-286 and a related site at Thr-292. p34cdc2 catalyzes the in vitro phosphorylation of MKK1 on both of these threonine residues and inactivates MKK1 enzymatic activity. Both sites are phosphorylated in vivo as well. The data presented in this report provide evidence that MKK1 is negatively regulated by threonine phosphorylation.



Blood ◽  
2014 ◽  
Vol 123 (7) ◽  
pp. 1102-1112 ◽  
Author(s):  
Tam Duong ◽  
Katarzyna Koltowska ◽  
Cathy Pichol-Thievend ◽  
Ludovic Le Guen ◽  
Frank Fontaine ◽  
...  

Key Points Haploinsufficiency of Sox18 reveals an important role for VEGFD in regulating blood vascular development in vivo in vertebrates. VEGFD acts through mitogen-activated protein kinase kinase–extracellular signal-regulated kinase to modulate the activity and nuclear concentration of endothelial-specific transcription factor SOX18.



Blood ◽  
2009 ◽  
Vol 114 (20) ◽  
pp. 4592-4600 ◽  
Author(s):  
Robert C. Doebele ◽  
Frank T. Schulze-Hoepfner ◽  
Jia Hong ◽  
Alexandre Chlenski ◽  
Benjamin D. Zeitlin ◽  
...  

Abstract Tumors depend upon angiogenesis for growth and metastasis. It is therefore critical to understand the inhibitory signaling mechanisms in endothelial cells that control angiogenesis. Epac is a cyclic adenosine 5′-monophosphate–activated guanine nucleotide exchange factor for Rap1. In this study, we show that activation of Epac or Rap1 leads to potent inhibition of angiogenesis in vivo. Epac/Rap1 activation down-regulates inhibitor of differentiation 1 (Id1), which negatively regulates thrombospondin-1 (TSP1), an inhibitor of angiogenesis. Consistent with this mechanism, activation of Epac/Rap 1 induces expression of TSP1; conversely, depletion of Epac reduces TSP1 levels in endothelial cells. Blockade of TSP1 binding to its receptor, CD36, rescues inhibition of chemotaxis or angiogenesis by activated Epac/Rap1. Mitogen-activated protein kinase kinase 5, a downstream mediator of vascular endothelial growth factor, antagonizes the effects of Epac/Rap1 by inducing Id1 and suppressing TSP1 expression. Finally, TSP1 is also secreted by fibroblasts in response to Epac/Rap1 activation. These results identify Epac and Rap1 as inhibitory regulators of the angiogenic process, implicate Id1 and TSP1 as downstream mediators of Epac/Rap1, and highlight a novel interplay between pro- and antiangiogenic signaling cascades involving multiple cell types within the angiogenic microenvironment.





2000 ◽  
Vol 352 (1) ◽  
pp. 145-154 ◽  
Author(s):  
Yvonne FLEMING ◽  
Christopher G. ARMSTRONG ◽  
Nick MORRICE ◽  
Andrew PATERSON ◽  
Michel GOEDERT ◽  
...  

Stress-activated protein kinase 1 (SAPK1), also called c-Jun N-terminal kinase (JNK), becomes activated in vivo in response to pro-inflammatory cytokines or cellular stresses. Its full activation requires the phosphorylation of a threonine and a tyrosine residue in a Thr-Pro-Tyr motif, which can be catalysed by the protein kinases mitogen-activated protein kinase kinase (MKK)4 and MKK7. Here we report that MKK4 shows a striking preference for the tyrosine residue (Tyr-185), and MKK7 a striking preference for the threonine residue (Thr-183) in three SAPK1/JNK1 isoforms tested (JNK1α1, JNK2α2 and JNK3α1). For this reason, MKK4 and MKK7 together produce a synergistic increase in the activity of each SAPK1/JNK isoform in vitro. The MKK7β variant, which is several hundred-fold more efficient in activating all three SAPK1/JNK isoforms than is MKK7α´, is equally specific for Thr-183. MKK7 also phosphorylates JNK2α2 at Thr-404 and Ser-407 in vitro, Ser-407 being phosphorylated much more rapidly than Thr-183 in vitro. Thr-404/Ser-407 are phosphorylated in unstimulated human KB cells and HEK-293 cells, and phosphorylation is increased in response to an osmotic stress (0.5M sorbitol). However, in contrast with Thr-183 and Tyr-185, the phosphorylation of Thr-404 and Ser-407 is not increased in response to other agonists that activate MKK7 and SAPK1/JNK, suggesting that phosphorylation of these residues is catalysed by another protein kinase, such as CK2, which also phosphorylates Thr-404 and Ser-407 in vitro. MKK3, MKK4 and MKK6 all show a strong preference for phosphorylation of the tyrosine residue of the Thr-Gly-Tyr motifs in their known substrates SAPK2a/p38, SAPK3/p38γ and SAPK4/p38δ. MKK7 also phosphorylates SAPK2a/p38 at a low rate (but not SAPK3/p38γ or SAPK4/p38δ), and phosphorylation occurs exclusively at the tyrosine residue, demonstrating that MKK7 is intrinsically a ‘dual-specific’ protein kinase.



Sign in / Sign up

Export Citation Format

Share Document