Gαs directly drives PDZ-RhoGEF signaling to Cdc42

Gα proteins promote dynamic adjustments of cell shape directed by actin-cytoskeleton reorganization via their respective RhoGEF effectors. For example, Gα13 binding to the RGS-homology (RH) domains of several RH-RhoGEFs allosterically activates these proteins, causing them to expose their catalytic Dbl-homology (DH)/pleckstrin-homology (PH) regions, which triggers downstream signals. However, whether additional Gα proteins might directly regulate the RH-RhoGEFs was not known. To explore this question, we first examined the morphological effects of expressing shortened RH-RhoGEF DH/PH constructs of p115RhoGEF/ARHGEF1, PDZ-RhoGEF (PRG)/ARHGEF11, and LARG/ARHGEF12. As expected, the three constructs promoted cell contraction and activated RhoA, known to be downstream of Gα13. Intriguingly, PRG DH/PH also induced filopodia-like cell protrusions and activated Cdc42. This pathway was stimulated by constitutively active Gαs (GαsQ227L), which enabled endogenous PRG to gain affinity for Cdc42. A chemogenetic approach revealed that signaling by Gs-coupled receptors, but not by those coupled to Gi or Gq, enabled PRG to bind Cdc42. This receptor-dependent effect, as well as CREB phosphorylation, was blocked by a construct derived from the PRG:Gαs-binding region, PRG-linker. Active Gαs interacted with isolated PRG DH and PH domains and their linker. In addition, this construct interfered with GαsQ227L's ability to guide PRG's interaction with Cdc42. Endogenous Gs-coupled prostaglandin receptors stimulated PRG binding to membrane fractions and activated signaling to PKA, and this canonical endogenous pathway was attenuated by PRG-linker. Altogether, our results demonstrate that active Gαs can recognize PRG as a novel effector directing its DH/PH catalytic module to gain affinity for Cdc42.

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Faculty Opinions recommendation of Migfilin and Mig-2 link focal adhesions to filamin and the actin cytoskeleton and function in cell shape modulation.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1012978.188315 ◽

2003 ◽

Author(s):

Carol Otey

Keyword(s):

Actin Cytoskeleton ◽

Cell Shape ◽

Focal Adhesions ◽

And Function ◽

Shape Modulation

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TNF-α Induces Actin Cytoskeleton Reorganization in Glomerular Epithelial Cells Involving Tyrosine Phosphorylation of Paxillin and Focal Adhesion Kinase

Molecular Medicine ◽

10.1007/bf03402127 ◽

1999 ◽

Vol 5 (6) ◽

pp. 382-392 ◽

Cited By ~ 56

Author(s):

S. B. Koukouritaki ◽

E. A. Vardaki ◽

E. A. Papakonstanti ◽

E. Lianos ◽

C. Stournaras ◽

...

Keyword(s):

Epithelial Cells ◽

Actin Cytoskeleton ◽

Focal Adhesion Kinase ◽

Tyrosine Phosphorylation ◽

Focal Adhesion ◽

Glomerular Epithelial Cells ◽

Cytoskeleton Reorganization ◽

Tnf Α

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Cofilin is a cAMP effector in mediating actin cytoskeleton reorganization and steroidogenesis in mouse and human adrenocortical tumor cells

Endocrine Abstracts ◽

10.1530/endoabs.49.ep20 ◽

2017 ◽

Author(s):

Rosa Catalano ◽

Erika Peverelli ◽

Elena Giardino ◽

Donatella Treppiedi ◽

Valentina Morelli ◽

...

Keyword(s):

Actin Cytoskeleton ◽

Tumor Cells ◽

Adrenocortical Tumor ◽

Cytoskeleton Reorganization

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Coxiella burnetii Induces Reorganization of the Actin Cytoskeleton in Human Monocytes

Infection and Immunity ◽

10.1128/iai.66.11.5527-5533.1998 ◽

1998 ◽

Vol 66 (11) ◽

pp. 5527-5533 ◽

Cited By ~ 40

Author(s):

Sonia Meconi ◽

Véronique Jacomo ◽

Patrice Boquet ◽

Didier Raoult ◽

Jean-Louis Mege ◽

...

Keyword(s):

Actin Cytoskeleton ◽

Coxiella Burnetii ◽

Actin Polymerization ◽

Q Fever ◽

Morphological Changes ◽

Critical Role ◽

Filamentous Actin ◽

Cytoskeleton Reorganization ◽

Membrane Protrusions ◽

Actin Protrusions

ABSTRACT Coxiella burnetii, an obligate intracellular bacterium which survives in myeloid cells, causes Q fever in humans. We previously demonstrated that virulent C. burnetiiorganisms are poorly internalized by monocytes compared to avirulent variants. We hypothesized that a differential mobilization of the actin cytoskeleton may account for this distinct phagocytic behavior. Scanning electron microscopy demonstrated that virulent C. burnetii stimulated profound and polymorphic changes in the morphology of THP-1 monocytes, consisting of membrane protrusions and polarized projections. These changes were transient, requiring 5 min to reach their maximum extent and vanishing after 60 min of incubation. In contrast, avirulent variants of C. burnetii did not induce any significant changes in cell morphology. The distribution of filamentous actin (F-actin) was then studied with a specific probe, bodipy phallacidin. Virulent C. burnetii induced a profound and transient reorganization of F-actin, accompanied by an increase in the F-actin content of THP-1 cells. F-actin was colocalized with myosin in cell protrusions, suggesting that actin polymerization and the tension of actin-myosin filaments play a role in C. burnetii-induced morphological changes. In addition, contact between the cell and the bacterium seems to be necessary to induce cytoskeleton reorganization. Bacterial supernatants did not stimulate actin remodeling, and virulent C. burnetii organisms were found in close apposition with F-actin protrusions. The manipulation of the actin cytoskeleton by C. burnetiimay therefore play a critical role in the internalization strategy of this bacterium.

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New interactions of invadopodia scaffold protein TKS5 with proteins that take part in actin cytoskeleton reorganization, endo-/exocytosis and membrane remodeling

Visnik ukrains'kogo tovaristva genetikiv i selekcioneriv ◽

10.7124/visnyk.utgis.16.2.1056 ◽

2019 ◽

Vol 16 (2) ◽

pp. 183-189

Author(s):

Y. M. Nemesh ◽

S. V. Kropyvko

Keyword(s):

Plasma Membrane ◽

Actin Cytoskeleton ◽

Scaffold Protein ◽

Scaffold Proteins ◽

Membrane Remodeling ◽

Sh3 Domains ◽

Protein Protein Interaction ◽

Cytoskeleton Reorganization ◽

New Interactions ◽

Cytoskeleton Rearrangement

Aim. TKS5 is a key scaffold protein of invadopodia. In its absence, the cells completely lose the ability to form invadopodia. This fact makes TKS5 a potential target for cancer cure and one of the central proteins in the investigation of cancer cell invasion. Additionally, the question remains about the function of TKS5 in normal cells. Therefore, in order to extend knowledge about TKS5 role in healthy and invasive cells, we tested the TKS5 interaction with the proteins involved in signal transduction: PLCγ1, SRC, CRK, CSK; the proteins involved in plasma membrane remodeling: AMPH1, BIN1, CIN85, ITSN1, ITSN2; the protein involved in the actin cytoskeleton rearrangement: CTTN. Methods. We used the GST Pull-down assay to identify the protein-protein interaction. Results. We revealed that TKS5 SH3 domains interact with CIN85. There were identified TKS5 interactions with SH3 domains of CTTN, ITSN1, ITSN2, AMPH1 and BIN1. Conclusions. TKS5 interacts with CIN85, CTTN, ITSN1, ITSN2, AMPH1 and BIN1, which take part in membrane remodeling, endo-/exocytosis and actin cytoskeleton rearrangement. Keywords: TKS5, scaffold proteins, actin cytoskeleton, plasma membrane.

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