scholarly journals Activation of the JNK pathway during dorsal closure in Drosophila requires the mixed lineage kinase, slipper

2002 ◽  
Vol 16 (3) ◽  
pp. 377-387 ◽  
Author(s):  
B. Stronach
Keyword(s):  
Dorsal Closure ◽  
Jnk Pathway ◽  
Mixed Lineage Kinase

scholarly journals The AF-6 Homolog Canoe Acts as a Rap1 Effector During Dorsal Closure of the Drosophila Embryo

Genetics ◽  
2003 ◽  
Vol 165 (1) ◽  
pp. 159-169
Author(s):  
Benjamin Boettner ◽  
Phoebe Harjes ◽  
Satoshi Ishimaru ◽  
Michael Heke ◽  
Hong Qing Fan ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Genetic Interaction ◽  
Critical Role ◽  
Adherens Junction ◽  
Small Gtpases ◽  
Drosophila Embryo ◽  
Dorsal Closure ◽  
Cell Sheets ◽  
Jnk Pathway

Abstract Rap1 belongs to the highly conserved Ras subfamily of small GTPases. In Drosophila, Rap1 plays a critical role in many different morphogenetic processes, but the molecular mechanisms executing its function are unknown. Here, we demonstrate that Canoe (Cno), the Drosophila homolog of mammalian junctional protein AF-6, acts as an effector of Rap1 in vivo. Cno binds to the activated form of Rap1 in a yeast two-hybrid assay, the two molecules colocalize to the adherens junction, and they display very similar phenotypes in embryonic dorsal closure (DC), a process that relies on the elongation and migration of epithelial cell sheets. Genetic interaction experiments show that Rap1 and Cno act in the same molecular pathway during DC and that the function of both molecules in DC depends on their ability to interact. We further show that Rap1 acts upstream of Cno, but that Rap1, unlike Cno, is not involved in the stimulation of JNK pathway activity, indicating that Cno has both a Rap1-dependent and a Rap1-independent function in the DC process.

Thorax closure in Drosophila: involvement of Fos and the JNK pathway

Development ◽  
1999 ◽  
Vol 126 (17) ◽  
pp. 3947-3956 ◽  
Author(s):  
J. Zeitlinger ◽  
D. Bohmann
Keyword(s):  
Functional Module ◽  
Cell Sheet ◽  
Dorsal Closure ◽  
Loss Of Function ◽  
Jnk Pathway ◽  
Insect Metamorphosis ◽  
Wing Imaginal Discs ◽  
The One ◽  
Jnk Activation

Dorsal closure, a morphogenetic movement during Drosophila embryogenesis, is controlled by the Drosophila JNK pathway, D-Fos and the phosphatase Puckered (Puc). To identify principles of epithelial closure processes, we studied another cell sheet movement that we term thorax closure, the joining of the parts of the wing imaginal discs which give rise to the adult thorax during metamorphosis. In thorax closure a special row of margin cells express puc and accumulate prominent actin fibres during midline attachment. Genetic data indicate a requirement of D-Fos and the JNK pathway for thorax closure, and a negative regulatory role of Puc. Furthermore, puc expression co-localises with elevated levels of D-Fos, is reduced in a JNK or D-Fos loss-of-function background and is ectopically induced after JNK activation. This suggests that Puc acts downstream of the JNK pathway and D-Fos to mediate a negative feed-back loop. Therefore, the molecular circuitry required for thorax closure is very similar to the one directing dorsal closure in the embryo, even though the tissues are not related. This finding supports the hypothesis that the mechanism controlling dorsal closure has been co-opted for thorax closure in the evolution of insect metamorphosis and may represent a more widely used functional module for tissue closure in other species as well.

scholarly journals The association of the JNK scaffold protein, WDR62, with the mixed lineage kinase 3, MLK3

MAP Kinase ◽  
2015 ◽  
Vol 4 (1) ◽  
Author(s):  
Miriam Hadad ◽  
Sharon Aviram ◽  
Ilona Darlyuk-Saadon ◽  
Ksenya Cohen-Katsenelson ◽  
Alan J. Whitmarsh ◽  
...  
Keyword(s):  
Kinase Activity ◽  
Scaffold Protein ◽  
Scaffold Proteins ◽  
Wd40 Repeat ◽  
Jnk Pathway ◽  
Kinase Activation ◽  
Mixed Lineage Kinase ◽  
Mitogen Activated Protein ◽  
Mixed Lineage Kinase 3 ◽  
Novel Scaffold

Mitogen-activated protein kinases (MAPKs) form a kinase tier module in which MAPK, MAP2K and MAP3K are held by scaffold proteins. The scaffold proteins serve as a protein platform for selective and spatial kinase activation. The precise mechanism by which the scaffold proteins function has not yet been fully explained. WD40-repeat protein 62, WDR62 is a novel scaffold protein of the c-Jun N-terminal kinase (JNK) pathway. WDR62 is a 1523 a.a. long protein with no significant sequence homology to a known gene. Previously WDR62 was shown to associate with JNK and MKK4/7 in a modular fashion. Here, we show that WDR62 is able to associate with multiple members of the MAP3K of the mixed lineage kinase family and we map WDR62-MLK3 interacting domains. We identify two separable interacting domains within WDR62 and MLK3 proteins that can cross associate. MLK3 association with WDR62 is independent of JNK and MKK4/7 domains and activities. CDC42 activation disrupts WDR62-MLK3 association independent of MLK3 kinase activity.

Sign in / Sign up

Export Citation Format

Share Document