scholarly journals Autoinhibition of GEF activity in intersectin 1 is mediated by the short SH3-DH domain linker

2010 ◽  
Vol 19 (11) ◽  
pp. 2164-2174 ◽  
Author(s):  
Carsten Kintscher ◽  
Silvia Wuertenberger ◽  
Roy Eylenstein ◽  
Theresia Uhlendorf ◽  
Yvonne Groemping
Keyword(s):  
Dh Domain

scholarly journals Selectivity of Guanine Nucleotide Exchange Factor-mediated Cdc42 activation in primary human endothelial cells

2019 ◽  
Author(s):  
Nathalie R. Reinhard ◽  
Sanne van der Niet ◽  
Anna Chertkova ◽  
Marten Postma ◽  
Peter L. Hordijk ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Single Cell ◽  
Rho Gtpases ◽  
Rho Gtpase ◽  
Actin Dynamics ◽  
Pleckstrin Homology Domain ◽  
Guanine Nucleotide ◽  
Nucleotide Exchange ◽  
Guanine Nucleotide Exchange ◽  
Dh Domain

AbstractThe Rho GTPase family is involved in actin dynamics and regulates the barrier function of the endothelium. One of the main barrier-promoting Rho GTPases is Cdc42, also known as cell division control protein 42 homolog. Currently, regulation of Cdc42-based signaling networks in endothelial cells (ECs) lack molecular details. To examine these, we focused on a subset of 15 Rho guanine nucleotide exchange factors (GEFs), which are expressed in the endothelium. By performing single cell FRET measurements with Rho GTPase biosensors in primary human ECs, we monitored GEF efficiency towards Cdc42 and Rac1. A new, single cell-based analysis was developed and used to enable the quantitative comparison of cellular activities of the full-length GEFs. Our data reveal a specific GEF dependent activation profile, with most efficient Cdc42 activation induced by PLEKHG2, FGD1, PLEKHG1 and pRex1 and the highest selectivity for FGD1. Additionally, we generated truncated GEF constructs that comprise only the catalytic dbl homology (DH) domain or together with the adjacent pleckstrin homology domain (DHPH). The DH domain by itself did not activate Cdc42, whereas the DHPH domain of ITSN1, ITSN2 and PLEKHG1 showed activity towards Cdc42. Together, our study characterized endothelial GEFs that may activate Cdc42, which will be of great value for the field of vascular biology.Abstract FigureGraphical Abstract

DrhoGEF3 encodes a new Drosophila DH domain protein that exhibits a highly dynamic embryonic expression pattern

2001 ◽  
Vol 211 (5) ◽  
pp. 263-267
Author(s):  
Marcus Hicks ◽  
Valerie O'Leary ◽  
Marian Wilkin ◽  
Sally Bee ◽  
Martin Humphries ◽  
...  
Keyword(s):  
Expression Pattern ◽  
Domain Protein ◽  
Dh Domain

scholarly journals A mammalian Rho-specific guanine-nucleotide exchange factor (p164-RhoGEF) without a pleckstrin homology domain

2002 ◽  
Vol 366 (3) ◽  
pp. 721-728 ◽  
Author(s):  
Ulrich RÜMENAPP ◽  
Andrea FREICHEL-BLOMQUIST ◽  
Burkhard WITTINGHOFER ◽  
Karl H. JAKOBS ◽  
Thomas WIELAND
Keyword(s):  
Gene Transcription ◽  
Rho Gtpases ◽  
Serum Response Factor ◽  
Full Length ◽  
Pleckstrin Homology Domain ◽  
Guanine Nucleotide ◽  
Nucleotide Exchange ◽  
Pleckstrin Homology ◽  
Guanine Nucleotide Exchange ◽  
Dh Domain

Rho GTPases, which are activated by specific guanine-nucleotide exchange factors (GEFs), play pivotal roles in several cellular functions. We identified a recently cloned human cDNA, namely KIAA0337, encoding a protein containing 1510 amino acids (p164). It contains a RhoGEF-specific Dbl homology (DH) domain but lacks their typical pleckstrin homology domain. The expression of the mRNA encoding p164 was found to be at least 4-fold higher in the heart than in other tissues. Recombinant p164 interacted with and induced GDP/GTP exchange at RhoA but not at Rac1 or Cdc42. p164-ΔC and p164-ΔN are p164 mutants that are truncated at the C- and N-termini respectively but contain the DH domain. In contrast with the full-length p164, expression of p164-ΔC and p164-ΔN strongly induced actin stress fibre formation and activated serum response factor-mediated and Rho-dependent gene transcription. Interestingly, p164-ΔN2, a mutant containing the C-terminus but having a defective DH domain, bound to p164-ΔC and suppressed the p164-ΔC-induced gene transcription. Overexpression of the full-length p164 inhibited M3 muscarinic receptor-induced gene transcription, whereas co-expression with Gβ1γ2 dimers induced transcriptional activity. It is concluded that p164-RhoGEF is a Rho-specific GEF with novel structural and regulatory properties and predominant expression in the heart. Apparently, its N- and C-termini interact with each other, thereby inhibiting its GEF activity.

scholarly journals In vitro kinetic study of the squalestatin tetraketide synthase dehydratase reveals the stereochemical course of a fungal highly reducing polyketide synthase

2017 ◽  
Vol 53 (10) ◽  
pp. 1727-1730 ◽  
Author(s):  
Emma Liddle ◽  
Alan Scott ◽  
Li-Chen Han ◽  
David Ivison ◽  
Thomas J. Simpson ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Kinetic Study ◽  
Fatty Acid Synthase ◽  
Polyketide Synthase ◽  
Substrate Selectivity ◽  
Dh Domain

The substrate selectivity of the isolated dehydratase (DH) domain of a fungal highly-reducing polyketide synthase is closely related to that of mammalian fatty acid synthase.

scholarly journals Structure and biosynthesis of deoxy-polyamine in X. bovienii

2021 ◽  
Author(s):  
Sebastian L Wenski ◽  
Natalie Berghaus ◽  
Nadine Keller ◽  
Helge B Bode
Keyword(s):  
Natural Products ◽  
Gene Clusters ◽  
Mass Spectrometric ◽  
Spectrometric Analysis ◽  
Heterologous Production ◽  
Biosynthetic Gene ◽  
Biosynthetic Gene Clusters ◽  
In Trans ◽  
In Cis ◽  
Dh Domain

Abstract Polyamine moieties have been described as part of the fabclavine and zeamine family of natural products. While the corresponding biosynthetic gene clusters have been found in many different proteobacteria, a unique BGC was identified in the entomopathogenic bacterium Xenorhabdus bovienii. Mass spectrometric analysis of a X. bovienii mutant strain revealed a new deoxy-polyamine. The corresponding biosynthesis includes two additional reductive steps, initiated by an additional dehydratase (DH) domain, which was not found in any other Xenorhabdus strain. Moreover, this DH domain could be successfully integrated into homologous biosynthesis pathways, leading to the formation of other deoxy-polyamines. Additional heterologous production experiments revealed that the DH domain could act in cis as well as in trans.

scholarly journals The Intersectin 2 Adaptor Links Wiskott Aldrich Syndrome Protein (WASp)-mediated Actin Polymerization to T Cell Antigen Receptor Endocytosis

2001 ◽  
Vol 194 (12) ◽  
pp. 1777-1787 ◽  
Author(s):  
Mary K.H. McGavin ◽  
Karen Badour ◽  
Lynne A. Hardy ◽  
Terrance J. Kubiseski ◽  
Jinyi Zhang ◽  
...  
Keyword(s):  
T Cell ◽  
Actin Polymerization ◽  
Rho Gtpase ◽  
Antigen Receptor ◽  
T Cell Antigen Receptor ◽  
Cell Antigen Receptor ◽  
Cell Antigen ◽  
Wiskott Aldrich Syndrome ◽  
Syndrome Protein ◽  
Dh Domain

Induction of T cell antigen receptor (TCR) endocytosis has a significant impact on TCR signaling and T cell behavior, but the molecular interactions coordinating internalization of the activated TCR are poorly understood. Previously we have shown that TCR endocytosis is regulated by the Wiskott Aldrich Syndrome protein (WASp), a cytosolic effector which, upon interaction with the cdc42 Rho GTPase, couples TCR engagement to Arp 2/3 complex-mediated actin polymerization. Here we report that WASp associates in T cells with intersectin 2, an endocytic adaptor containing multiple domains including a Dbl homology (DH) domain with the potential to activate Rho GTPases. Intersectin 2 association with WASp increases after TCR engagement, and its overexpression in Cos-7 cells induces WASp translocation to endocytic vesicles within which intersectin 2 colocalizes with both WASp and cdc42. Intersectin 2, but not a DH domain-deleted (ΔDH) form of intersectin 2, and stimulation via the TCR also trigger the activation of cdc42. Induction of TCR internalization is also augmented by intersectin 2 and severely impaired by latrunculin B treatment. Thus, intersection 2 appears to function cooperatively with WASp and cdc42 to link the clathrin endocytic machinery to WASp-mediated actin polymerization and ultimately to occupancy-induced TCR endocytosis.

scholarly journals The first DEP domain of the RhoGEF P-Rex1 autoinhibits activity and contributes to membrane binding

2020 ◽  
Vol 295 (36) ◽  
pp. 12635-12647
Author(s):  
Sandeep K. Ravala ◽  
Jesse B. Hopkins ◽  
Caroline B. Plescia ◽  
Samantha R. Allgood ◽  
Madison A. Kane ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Phosphorylation Site ◽  
Solution Conformation ◽  
Domain Swap ◽  
Rac Gtpases ◽  
Highly Correlated ◽  
Charged Membranes ◽  
Dh Domain ◽  
Basic Loop ◽  
Kinase A

Phosphatidylinositol (3,4,5)-trisphosphate (PIP3)-dependent Rac exchanger 1 (P-Rex1) catalyzes the exchange of GDP for GTP on Rac GTPases, thereby triggering changes in the actin cytoskeleton and in transcription. Its overexpression is highly correlated with the metastasis of certain cancers. P-Rex1 recruitment to the plasma membrane and its activity are regulated via interactions with heterotrimeric Gβγ subunits, PIP3, and protein kinase A (PKA). Deletion analysis has further shown that domains C-terminal to its catalytic Dbl homology (DH) domain confer autoinhibition. Among these, the first dishevelled, Egl-10, and pleckstrin domain (DEP1) remains to be structurally characterized. DEP1 also harbors the primary PKA phosphorylation site, suggesting that an improved understanding of this region could substantially increase our knowledge of P-Rex1 signaling and open the door to new selective chemotherapeutics. Here we show that the DEP1 domain alone can autoinhibit activity in context of the DH/PH-DEP1 fragment of P-Rex1 and interacts with the DH/PH domains in solution. The 3.1 Å crystal structure of DEP1 features a domain swap, similar to that observed previously in the Dvl2 DEP domain, involving an exposed basic loop that contains the PKA site. Using purified proteins, we show that although DEP1 phosphorylation has no effect on the activity or solution conformation of the DH/PH-DEP1 fragment, it inhibits binding of the DEP1 domain to liposomes containing phosphatidic acid. Thus, we propose that PKA phosphorylation of the DEP1 domain hampers P-Rex1 binding to negatively charged membranes in cells, freeing the DEP1 domain to associate with and inhibit the DH/PH module.

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