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Title: Structure and regulation of human epithelial cell transforming 2 protein

Journal Article · · Proceedings of the National Academy of Sciences of the United States of America
 [1];  [2];  [3];  [4];  [2];  [2];  [4];  [2];  [2];  [2];  [4];  [2]
  1. Tsinghua Univ., Beijing (China); Peking Univ., Beijing (China)
  2. Tsinghua Univ., Beijing (China)
  3. Tsinghua Univ., Beijing (China); Waigaoqiao Free Trade Zone, Shanghai (China)
  4. Peking Univ., Beijing (China)

Epithelial cell transforming 2 (Ect2) protein activates Rho GTPases and controls cytokinesis and many other cellular processes. Dysregulation of Ect2 is associated with various cancers. Here, we report the crystal structure of human Ect2 and complementary mechanistic analyses. The data show the C-terminal PH domain of Ect2 folds back and blocks the canonical RhoA-binding site at the catalytic center of the DH domain, providing a mechanism of Ect2 autoinhibition. Ect2 is activated by binding of GTP-bound RhoA to the PH domain, which suggests an allosteric mechanism of Ect2 activation and a positive-feedback loop reinforcing RhoA signaling. Furthermore this bimodal RhoA binding of Ect2 is unusual and was confirmed with Förster resonance energy transfer (FRET) and hydrogen–deuterium exchange mass spectrometry (HDX-MS) analyses. Several recurrent cancer-associated mutations map to the catalytic and regulatory interfaces, and dysregulate Ect2 in vitro and in vivo. Together, our findings provide mechanistic insights into Ect2 regulation in normal cells and under disease conditions.

Research Organization:
Argonne National Laboratory (ANL), Argonne, IL (United States)
Sponsoring Organization:
National Natural Science Foundation of China (NSFC)
Grant/Contract Number:
2019YFA0508900; 2017YFA0102900; 31570731; 31270762; 31630046
OSTI ID:
1601858
Journal Information:
Proceedings of the National Academy of Sciences of the United States of America, Vol. 117, Issue 2; ISSN 0027-8424
Publisher:
National Academy of SciencesCopyright Statement
Country of Publication:
United States
Language:
ENGLISH
Citation Metrics:
Cited by: 25 works
Citation information provided by
Web of Science

References (66)

The Tandem BRCT Domains of Ect2 Are Required for Both Negative and Positive Regulation of Ect2 in Cytokinesis journal November 2004
Requirement For C-terminal Sequences in Regulation of Ect2 Guanine Nucleotide Exchange Specificity and Transformation journal April 2004
Deregulation and Mislocalization of the Cytokinesis Regulator ECT2 Activate the Rho Signaling Pathways Leading to Malignant Transformation journal November 2003
An Anillin-Ect2 Complex Stabilizes Central Spindle Microtubules at the Cortex during Cytokinesis journal April 2012
Centralspindlin and α-catenin regulate Rho signalling at the epithelial zonula adherens journal July 2012
RNF43 is frequently mutated in colorectal and endometrial cancers journal October 2014
CRYSOL – a Program to Evaluate X-ray Solution Scattering of Biological Macromolecules from Atomic Coordinates journal December 1995
Determination of the regularization parameter in indirect-transform methods using perceptual criteria journal August 1992
Structure of G q-p63RhoGEF-RhoA Complex Reveals a Pathway for the Activation of RhoA by GPCRs journal December 2007
PRIMUS: a Windows PC-based system for small-angle scattering data analysis journal September 2003
Human Ect2 Is an Exchange Factor for Rho Gtpases, Phosphorylated in G2/M Phases, and Involved in Cytokinesis journal November 1999
Towards automated crystallographic structure refinement with phenix.refine journal March 2012
A Method for Helical RNA Global Structure Determination in Solution Using Small-Angle X-Ray Scattering and NMR Measurements journal October 2009
ECT2 regulates the Rho/ERK signalling axis to promote early recurrence in human hepatocellular carcinoma journal June 2015
Ect2/Pbl Acts via Rho and Polarity Proteins to Direct the Assembly of an Isotropic Actomyosin Cortex upon Mitotic Entry journal March 2015
A small GTPase molecular switch regulates epigenetic centromere maintenance by stabilizing newly incorporated CENP-A journal November 2010
Centralspindlin in Rappaport’s cleavage signaling journal May 2016
q Directly Activates p63RhoGEF and Trio via a Conserved Extension of the Dbl Homology-associated Pleckstrin Homology Domain journal July 2007
An ECT2–centralspindlin complex regulates the localization and function of RhoA journal August 2005
Evolutionary optimization of fluorescent proteins for intracellular FRET journal February 2005
Polo-Like Kinase 1 Directs Assembly of the HsCyk-4 RhoGAP/Ect2 RhoGEF Complex to Initiate Cleavage Furrow Formation journal May 2009
Plk1 Self-Organization and Priming Phosphorylation of HsCYK-4 at the Spindle Midzone Regulate the Onset of Division in Human Cells journal May 2009
Oncogene ect2 is related to regulators of small GTP-binding proteins journal April 1993
Oncogenic Activity of Ect2 Is Regulated through Protein Kinase Cι-mediated Phosphorylation journal December 2010
Activated RhoA Is a Positive Feedback Regulator of the Lbc Family of Rho Guanine Nucleotide Exchange Factor Proteins journal March 2013
Structural Evidence for Feedback Activation by Ras·GTP of the Ras-Specific Nucleotide Exchange Factor SOS journal March 2003
The Genomic Landscape of Pediatric Ewing Sarcoma journal September 2014
Cytokinesis regulator ECT2 changes its conformation through phosphorylation at Thr-341 in G2/M phase journal September 2005
Phosphorylation-Dependent Assembly and Coordination of the DNA Damage Checkpoint Apparatus by Rad4TopBP1 journal September 2013
Ect2 links the PKCι–Par6α complex to Rac1 activation and cellular transformation journal July 2009
A ‘synthetic-sickness’ screen for senescence re-engagement targets in mutant cancer backgrounds journal August 2017
The cBio Cancer Genomics Portal: An Open Platform for Exploring Multidimensional Cancer Genomics Data: Figure 1. journal May 2012
NOTCH1 Mutations Occur Early during Cutaneous Squamous Cell Carcinogenesis journal October 2014
Crystal Structure of the Dbl and Pleckstrin Homology Domains from the Human Son of Sevenless Protein journal October 1998
Targeting of the RhoGEF Ect2 to the Equatorial Membrane Controls Cleavage Furrow Formation during Cytokinesis journal December 2011
Mutational landscape of gastric adenocarcinoma in Chinese: Implications for prognosis and therapy journal January 2015
Comprehensive molecular characterization of human colon and rectal cancer journal July 2012
Activator–inhibitor coupling between Rho signalling and actin assembly makes the cell cortex an excitable medium journal October 2015
RhoA activation during polarization and cytokinesis of the early Caenorhabditis elegans embryo is differentially dependent on NOP-1 and CYK-4 journal October 2012
Rho guanine nucleotide exchange factors: regulators of Rho GTPase activity in development and disease journal September 2013
Whole Exome Sequencing Identifies Frequent Somatic Mutations in Cell-Cell Adhesion Genes in Chinese Patients with Lung Squamous Cell Carcinoma journal October 2015
Nucleotide Exchange Factor ECT2 Interacts with the Polarity Protein Complex Par6/Par3/Protein Kinase C  (PKC ) and Regulates PKC  Activity journal July 2004
Phosphorylation of the cytokinesis regulator ECT2 at G2/M phase stimulates association of the mitotic kinase Plk1 and accumulation of GTP-bound RhoA journal October 2005
Involvement of Epithelial Cell Transforming Sequence-2 Oncoantigen in Lung and Esophageal Cancer Progression journal January 2009
Molecular Mechanism of Cytokinesis journal June 2019
Mechanistic Insights into the Anchorage of the Contractile Ring by Anillin and Mid1 journal May 2015
Structural basis for the selective activation of Rho GTPases by Dbl exchange factors journal May 2002
Plasma Membrane Association but Not Midzone Recruitment of RhoGEF ECT2 Is Essential for Cytokinesis journal December 2016
Sequential functioning of the ECT-2 RhoGEF, RHO-1 and CDC-42 establishes cell polarity in Caenorhabditis elegans embryos journal August 2006
Polo-like Kinase 1 Triggers the Initiation of Cytokinesis in Human Cells by Promoting Recruitment of the RhoGEF Ect2 to the Central Spindle journal May 2007
The Caenorhabditis elegans ect‐2 RhoGEF gene regulates cytokinesis and migration of epidermal P cells journal December 2005
Anillin Is a Scaffold Protein That Links RhoA, Actin, and Myosin during Cytokinesis journal January 2008
Novel mutations target distinct subgroups of medulloblastoma journal June 2012
The Role of Ect2 Nuclear RhoGEF Activity in Ovarian Cancer Cell Transformation journal November 2013
SWISS-MODEL: homology modelling of protein structures and complexes journal May 2018
Experiments concerning the cleavage stimulus in sand dollar eggs journal October 1961
Ect2-Dependent rRNA Synthesis Is Required for KRAS-TRP53 -Driven Lung Adenocarcinoma journal February 2017
ConSurf 2016: an improved methodology to estimate and visualize evolutionary conservation in macromolecules journal May 2016
Accurate assessment of mass, models and resolution by small-angle scattering journal April 2013
Cytokinesis defects and cancer journal December 2018
Internal dynamics control activation and activity of the autoinhibited Vav DH domain journal May 2008
The RhoGAP activity of CYK-4/MgcRacGAP functions non-canonically by promoting RhoA activation during cytokinesis journal August 2015
Structural basis of ubiquitin modification by the Legionella effector SdeA journal May 2018
Spatiotemporal Regulation of RhoA during Cytokinesis journal May 2018
The guanine nucleotide exchange factor (GEF) Ect2 is an oncogene in human cancer journal January 2010
Crystal structure of triple-BRCT-domain of ECT2 and insights into the binding characteristics to CYK-4 journal July 2014