scholarly journals DAPLE and MPDZ bind to each other and cooperate to promote apical cell constriction

2019 ◽  
Vol 30 (16) ◽  
pp. 1900-1910 ◽  
Author(s):  
Arthur Marivin ◽  
Mikel Garcia-Marcos
Keyword(s):  
G Protein ◽  
Cultured Cells ◽  
Apical Cell ◽  
Cell Junctions ◽  
Binding Motif ◽  
Apical Constriction ◽  
Protein Activation ◽  
Neuroepithelial Cells ◽  
Two Factors ◽  
Apical Junctions

Dishevelled-Associating Protein with a high frequency of LEucines (DAPLE) belongs to a group of unconventional activators of heterotrimeric G-proteins that are cytoplasmic factors rather than membrane proteins of the G-protein–coupled receptor superfamily. During neurulation, DAPLE localizes to apical junctions of neuroepithelial cells and promotes apical cell constriction via G-protein activation. While junctional localization of DAPLE is necessary for this function, the factors it associates with at apical junctions or how they contribute to DAPLE-mediated apical constriction are unknown. MPDZ is a multi-PDZ (PSD95/DLG1/ZO-1) domain scaffold present at apical cell junctions whose mutation in humans is linked to nonsyndromic congenital hydrocephalus (NSCH). DAPLE contains a PDZ-binding motif (PBM) and is also mutated in human NSCH, so we investigated the functional relationship between both proteins. DAPLE colocalized with MPDZ at apical cell junctions and bound directly to the PDZ3 domain of MPDZ via its PBM. Much like DAPLE, MPDZ is induced during neurulation in Xenopus and is required for apical constriction of neuroepithelial cells and subsequent neural plate bending. MPDZ depletion also blunted DAPLE-­mediated apical constriction of cultured cells. These results show that DAPLE and MPDZ, two factors genetically linked to NSCH, function as cooperative partners at apical junctions and are required for proper tissue remodeling during early stages of neurodevelopment.

scholarly journals GPCR-independent activation of G proteins promotes apical cell constriction in vivo

2019 ◽  
Vol 218 (5) ◽  
pp. 1743-1763 ◽  
Author(s):  
Arthur Marivin ◽  
Veronika Morozova ◽  
Isha Walawalkar ◽  
Anthony Leyme ◽  
Dmitry A. Kretov ◽  
...  
Keyword(s):  
G Protein ◽  
G Proteins ◽  
Apical Cell ◽  
Neural Plate ◽  
Cell Junctions ◽  
Epithelial Tissue ◽  
G Protein Signaling ◽  
Protein Signaling ◽  
Apical Constriction

Heterotrimeric G proteins are signaling switches that control organismal morphogenesis across metazoans. In invertebrates, specific GPCRs instruct G proteins to promote collective apical cell constriction in the context of epithelial tissue morphogenesis. In contrast, tissue-specific factors that instruct G proteins during analogous processes in vertebrates are largely unknown. Here, we show that DAPLE, a non-GPCR protein linked to human neurodevelopmental disorders, is expressed specifically in the neural plate of Xenopus laevis embryos to trigger a G protein signaling pathway that promotes apical cell constriction during neurulation. DAPLE localizes to apical cell–cell junctions in the neuroepithelium, where it activates G protein signaling to drive actomyosin-dependent apical constriction and subsequent bending of the neural plate. This function is mediated by a Gα-binding-and-activating (GBA) motif that was acquired by DAPLE in vertebrates during evolution. These findings reveal that regulation of tissue remodeling during vertebrate development can be driven by an unconventional mechanism of heterotrimeric G protein activation that operates in lieu of GPCRs.

scholarly journals Cell non-autonomy amplifies disruption of neurulation by mosaic Vangl2 deletion in mice

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Gabriel L. Galea ◽  
Eirini Maniou ◽  
Timothy J. Edwards ◽  
Abigail R. Marshall ◽  
Ioakeim Ampartzidis ◽  
...  
Keyword(s):  
Cell Polarity ◽  
Planar Cell Polarity ◽  
Myosin Ii ◽  
Apical Cell ◽  
Neural Tube Closure ◽  
Congenital Defects ◽  
Cell Cortex ◽  
Apical Constriction ◽  
Neuroepithelial Cells ◽  
Tube Closure

AbstractPost-zygotic mutations that generate tissue mosaicism are increasingly associated with severe congenital defects, including those arising from failed neural tube closure. Here we report that neural fold elevation during mouse spinal neurulation is vulnerable to deletion of the VANGL planar cell polarity protein 2 (Vangl2) gene in as few as 16% of neuroepithelial cells. Vangl2-deleted cells are typically dispersed throughout the neuroepithelium, and each non-autonomously prevents apical constriction by an average of five Vangl2-replete neighbours. This inhibition of apical constriction involves diminished myosin-II localisation on neighbour cell borders and shortening of basally-extending microtubule tails, which are known to facilitate apical constriction. Vangl2-deleted neuroepithelial cells themselves continue to apically constrict and preferentially recruit myosin-II to their apical cell cortex rather than to apical cap localisations. Such non-autonomous effects can explain how post-zygotic mutations affecting a minority of cells can cause catastrophic failure of morphogenesis leading to clinically important birth defects.

scholarly journals Cdc42 Regulates Apical Junction Formation in Human Bronchial Epithelial Cells through PAK4 and Par6B

2010 ◽  
Vol 21 (17) ◽  
pp. 2996-3006 ◽  
Author(s):  
Sean W. Wallace ◽  
Joanne Durgan ◽  
Dan Jin ◽  
Alan Hall
Keyword(s):  
Epithelial Cells ◽  
Apical Cell ◽  
Lung Epithelial Cells ◽  
Cell Junctions ◽  
Epithelial Cell Line ◽  
Dependent Manner ◽  
Bronchial Epithelial ◽  
Junction Formation ◽  
Apical Junctions ◽  
Cell Cell

Cdc42 has been implicated in numerous biochemical pathways during epithelial morphogenesis, including the control of spindle orientation during mitosis, the establishment of apical-basal polarity, the formation of apical cell–cell junctions, and polarized secretion. To investigate the signaling pathways through which Cdc42 mediates these diverse effects, we have screened an siRNA library corresponding to the 36 known Cdc42 target proteins, in a human bronchial epithelial cell line. Two targets, PAK4 and Par6B, were identified as necessary for the formation of apical junctions. PAK4 is recruited to nascent cell–cell contacts in a Cdc42-dependent manner, where it is required for the maturation of primordial junctions into apical junctions. PAK4 kinase activity is essential for junction maturation, but overexpression of an activated PAK4 mutant disrupts this process. Par6B, together with its binding partner aPKC, is necessary both for junction maturation and for the retention of PAK4 at sites of cell–cell contact. This study demonstrates that controlled regulation of PAK4 is required for apical junction formation in lung epithelial cells and highlights potential cross-talk between two Cdc42 targets, PAK4 and Par6B.

scholarly journals Cell non-autonomy amplifies disruption of neurulation by mosaic Vangl2 deletion

2020 ◽  
Author(s):  
Gabriel Galea ◽  
Eirini Maniou ◽  
Abigail R Marshall ◽  
Nicholas DE Greene ◽  
Andrew J Copp
Keyword(s):  
Planar Cell Polarity ◽  
Myosin Ii ◽  
Apical Cell ◽  
Neural Tube Closure ◽  
Congenital Defects ◽  
Cell Cortex ◽  
Core Component ◽  
Apical Constriction ◽  
Neuroepithelial Cells ◽  
Tube Closure

Abstract Post-zygotic mutations that generate tissue mosaicism are increasingly associated with severe congenital defects, including those arising from failed neural tube closure. We observed that elevation of the neural folds during mouse spinal neurulation is vulnerable to deletion of the planar cell polarity core component Van Gogh-like (Vangl)2 in as few as 16% of neuroepithelial cells. Vangl2-deleted cells are typically dispersed throughout the neuroepithelium, and each non-autonomously prevents apical constriction by an average of five Vangl2-replete neighbours. This inhibition of apical constriction involves reduced myosin-II recruitment to neighbour cell borders and shortening of basally-extending microtubule tails, which are known to facilitate apical constriction. Vangl2-deleted cells themselves continue to apically constrict and preferentially recruit myosin-II to their apical cell cortex rather than to apical cap sarcomere-like organisations. Such non-autonomous effects can explain how post-zygotic mutations affecting a minority of cells can cause catastrophic failure of morphogenesis leading to clinically important birth defects.

Opioid-Activated Postsynaptic, Inward Rectifying Potassium Currents in Whole Cell Recordings in Substantia Gelatinosa Neurons

1998 ◽  
Vol 80 (6) ◽  
pp. 2954-2962 ◽  
Author(s):  
S. P. Schneider ◽  
W. A. Eckert ◽  
A. R. Light
Keyword(s):  
Membrane Potential ◽  
G Protein ◽  
Potassium Currents ◽  
Substantia Gelatinosa ◽  
Opioid Agonist ◽  
Membrane Hyperpolarization ◽  
Whole Cell ◽  
Protein Activation ◽  
G Protein Activation ◽  
Whole Cell Recordings

Schneider, S. P., W. A. Eckert III, and A. R. Light. Opioid-activated postsynaptic, inward rectifying potassium currents in whole cell recordings in substantia gelatinosa neurons. J. Neurophysiol. 80: 2954–2962, 1998. Using tight-seal, whole cell recordings from isolated transverse slices of hamster and rat spinal cord, we investigated the effects of the μ-opioid agonist (d-Ala2, N-Me-Phe4,Gly5-ol)-enkephalin (DAMGO) on the membrane potential and conductance of substantia gelatinosa (SG) neurons. We observed that bath application of 1–5 μM DAMGO caused a robust and repeatable hyperpolarization in membrane potential ( V m) and decrease in neuronal input resistance ( R N) in 60% (27/45) of hamster neurons and 39% (9/23) of rat neurons, but significantly only when ATP (2 mM) and guanosine 5′-triphosphate (GTP; 100 μM) were included in the patch pipette internal solution. An ED50 of 50 nM was observed for the hyperpolarization in rat SG neurons. Because G-protein mediation of opioid effects has been shown in other systems, we tested if the nucleotide requirement for opioid hyperpolarization in SG neurons was due to G-protein activation. GTP was replaced with the nonhydrolyzable GTP analogue guanosine-5′- O-(3-thiotriphosphate) (GTP-γ-S; 100 μM), which enabled DAMGO to activate a nonreversible membrane hyperpolarization. Further, intracellular application of guanosine-5′- O-(2-thiodiphosphate) (GDP-β-S; 500 μM), which blocks G-protein activation, abolished the effects of DAMGO. We conclude that spinal SG neurons are particularly susceptible to dialysis of GTP by whole cell recording techniques. Moreover, the depletion of GTP leads to the inactivation of G-proteins that mediate μ-opioid activation of an inward-rectifying, potassium conductance in these neurons. These results explain the discrepancy between the opioid-activated hyperpolarization in SG neurons observed in previous sharp electrode experiments and the more recent failures to observe these effects with whole cell patch techniques.

scholarly journals Light-activated rhodopsin induces structural binding motif in G protein   subunit

1998 ◽  
Vol 95 (8) ◽  
pp. 4270-4275 ◽  
Author(s):  
O. G. Kisselev ◽  
J. Kao ◽  
J. W. Ponder ◽  
Y. C. Fann ◽  
N. Gautam ◽  
...  
Keyword(s):  
G Protein ◽  
Binding Motif ◽  
Protein Subunit
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