WAVE signalling: from biochemistry to biology

2006 ◽  
Vol 34 (1) ◽  
pp. 73-76 ◽  
Author(s):  
S.H. Soderling ◽  
J.D. Scott

The small GTPases Rho, Rac and Cdc42 (cell-division cycle 42) function as molecular switches to modulate the actin cytoskeleton. They achieve this by modulating the activity of downstream cellular targets. One group of Rho GTPase effectors, WAVE (Wiskott–Aldrich syndrome protein verprolin homologous)-1, WAVE-2 and WAVE-3, function as scaffolds for actin-based signalling complexes. The present review highlights current knowledge regarding the biochemistry of the WAVE signalling complexes and their biological significance.

Author(s):  
Fabienne Podieh ◽  
Peter L. Hordijk

Cullin3-based ubiquitin E3 ligases induce ubiquitination of substrates leading to their proteasomal or lysosomal degradation. BTB proteins serve as adaptors by binding to Cullin3 and recruiting substrate proteins, which enables specific recognition of a broad spectrum of targets. Hence, Cullin3 and its adaptors are involved in myriad cellular processes and organ functions. Cullin3-based ubiquitin E3 ligase complexes target small GTPases of the Rho subfamily, which are key regulators of cytoskeletal dynamics and cell adhesion. In this mini review, we discuss recent insights in Cullin3-mediated regulation of Rho GTPases and their impact on cellular function and disease. Intriguingly, upstream regulators of Rho GTPases are targeted by Cullin3 complexes as well. Thus, Rho GTPase signaling is regulated by Cullin3 on multiple levels. In addition, we address current knowledge of Cullin3 in regulating vascular function, focusing on its prominent role in endothelial barrier function, angiogenesis and the regulation of blood pressure.


Cells ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 2279
Author(s):  
Silvestar Beljan ◽  
Maja Herak Bosnar ◽  
Helena Ćetković

Non-bilaterian animals consist of four phyla; Porifera, Cnidaria, Ctenophora, and Placozoa. These early-diverging animals are crucial for understanding the evolution of the entire animal lineage. The Rho family of proteins make up a major branch of the Ras superfamily of small GTPases, which function as key molecular switches that play important roles in converting and amplifying external signals into cellular responses. This review represents a compilation of the current knowledge on Rho-family GTPases in non-bilaterian animals, the available experimental data about their biochemical characteristics and functions, as well as original bioinformatics analysis, in order to gain a general insight into the evolutionary history of Rho-family GTPases in simple animals.


2003 ◽  
Vol 285 (5) ◽  
pp. C1116-C1121 ◽  
Author(s):  
Alexey Y. Kolyada ◽  
Kathleen N. Riley ◽  
Ira M. Herman

Rho family small GTPases (Rho, Rac, and Cdc42) play an important role in cell motility, adhesion, and cell division by signaling reorganization of the actin cytoskeleton. Here, we report an isoactin-specific, Rho GTPase-dependent signaling cascade in cells simultaneously expressing smooth muscle and nonmuscle actin isoforms. We transfected primary cultures of microvascular pericytes, cells related to vascular smooth muscle cells, with various Rho-related and Rho-specific expression plasmids. Overexpression of dominant positive Rho resulted in the formation of nonmuscle actin-containing stress fibers. At the same time, α-vascular smooth muscle actin (αVSMactin) containing stress fibers were disassembled, resulting in a dramatic reduction in cell size. Rho activation also yielded a disassembly of smooth muscle myosin and nonmuscle myosin from stress fibers. Overexpression of wild-type Rho had similar but less dramatic effects. In contrast, dominant negative Rho and C3 exotransferase or dominant positive Rac and Cdc42 expression failed to alter the actin cytoskeleton in an isoform-specific manner. The loss of smooth muscle contractile protein isoforms in pericyte stress fibers, together with a concomitant decrease in cell size, suggests that Rho activation influences “contractile” phenotype in an isoactin-specific manner. This, in turn, should yield significant alteration in microvascular remodeling during developmental and pathologic angiogenesis.


2012 ◽  
Vol 40 (1) ◽  
pp. 268-272 ◽  
Author(s):  
Lifei Fan ◽  
Harry Mellor

The Rif GTPase is a recent addition to small Rho GTPase family; it shares low homology with other members in the family and evolutionarily parallels with the development of vertebrates. Rif has the conserved Rho GTPase domain structures and cycles between a GDP-bound inactive form and a GTP-bound active form. In its active form, Rif signals through multiple downstream effectors. In the present review, our aim is to summarize the current information about the Rif effectors and how Rif remodels actin cytoskeleton in many aspects.


2001 ◽  
Vol 114 (21) ◽  
pp. 3795-3803 ◽  
Author(s):  
Torsten Wittmann ◽  
Clare M. Waterman-Storer

Migrating cells display a characteristic polarization of the actin cytoskeleton. Actin filaments polymerise in the protruding front of the cell whereas actin filament bundles contract in the cell body, which results in retraction of the cell’s rear. The dynamic organization of the actin cytoskeleton provides the force for cell motility and is regulated by small GTPases of the Rho family, in particular Rac1, RhoA and Cdc42. Although the microtubule cytoskeleton is also polarized in a migrating cell, and microtubules are essential for the directed migration of many cell types, their role in cell motility is not well understood at a molecular level. Here, we discuss the potential molecular mechanisms for interplay of microtubules, actin and Rho GTPase signalling in cell polarization and motility. Recent evidence suggests that microtubules locally modulate the activity of Rho GTPases and, conversely, Rho GTPases might be responsible for the initial polarization of the microtubule cytoskeleton. Thus, microtubules might be part of a positive feedback mechanism that maintains the stable polarization of a directionally migrating cell.


2019 ◽  
Author(s):  
Michelle S. Lu ◽  
David G. Drubin

AbstractSmall GTPases of the Rho family are binary molecular switches that regulate a variety of processes including cell migration and oriented cell divisions. Known Cdc42 effectors include proteins involved in cytoskeletal remodeling and kinase-dependent transcription induction, but none involved in the maintenance of nuclear envelope integrity or endoplasmic reticulum (ER) morphology. Maintenance of nuclear envelope integrity requires the EndoSomal Complexes Required for Transport (ESCRT) proteins, but how they are regulated in this process remains unknown. Here we show by live-cell imaging a novel Cdc42 localization with ESCRT proteins at sites of nuclear envelope and ER fission, and by genetic analysis, uncover a unique Cdc42 function in regulation of ESCRT proteins at the nuclear envelope and sites of ER tubule fission. Our findings implicate Cdc42 in nuclear envelope sealing and ER remodeling, where it regulates ESCRT disassembly to maintain nuclear envelope integrity and proper ER architecture.SummaryThe small Rho GTPase Cdc42 is a well-known regulator of cytoskeletal rearrangement and polarity development in all eukaryotic cell types. Here, Lu and Drubin report the serendipitous discovery of a novel Cdc42-ESCRT-nuclear envelope/endoplasmic reticulum connection.


2016 ◽  
Vol 30 (3) ◽  
pp. 278-289 ◽  
Author(s):  
Yan Zuo ◽  
Wonkyung Oh ◽  
Arzu Ulu ◽  
Jeffrey A. Frost

Abstract Ras homolog (Rho) family small GTPases are critical regulators of actin cytoskeletal organization, cell motility, proliferation, and survival. Surprisingly, the large majority of the studies underlying our knowledge of Rho protein function have been carried out in cultured cells, and it is only recently that researchers have begun to assess Rho GTPase regulation and function in vivo. The purpose of this review is to evaluate our current knowledge of Rho GTPase function in mouse mammary gland development, tumorigenesis and metastasis. Although our knowledge is still incomplete, these studies are already uncovering important themes as to the physiological roles of Rho GTPase signaling in normal mammary gland development and function. Essential contributions of Rho proteins to breast cancer initiation, tumor progression, and metastatic dissemination have also been identified.


2003 ◽  
Vol 371 (2) ◽  
pp. 233-241 ◽  
Author(s):  
Britta QUALMANN ◽  
Harry MELLOR

The members of the Rho subfamily of small GTPases are key regulators of the actin cytoskeleton. However, recent studies have provided evidence for multiple additional roles for these signalling proteins in controlling endocytic traffic. Here we review our current understanding of Rho GTPase action within the endocytic pathway and examine the potential points of convergence with the more established, actin-based functions of these signalling proteins.


Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1592
Author(s):  
Vedrana Filić ◽  
Lucija Mijanović ◽  
Darija Putar ◽  
Antea Talajić ◽  
Helena Ćetković ◽  
...  

Both Dictyostelium amoebae and mammalian cells are endowed with an elaborate actin cytoskeleton that enables them to perform a multitude of tasks essential for survival. Although these organisms diverged more than a billion years ago, their cells share the capability of chemotactic migration, large-scale endocytosis, binary division effected by actomyosin contraction, and various types of adhesions to other cells and to the extracellular environment. The composition and dynamics of the transient actin-based structures that are engaged in these processes are also astonishingly similar in these evolutionary distant organisms. The question arises whether this remarkable resemblance in the cellular motility hardware is accompanied by a similar correspondence in matching software, the signalling networks that govern the assembly of the actin cytoskeleton. Small GTPases from the Rho family play pivotal roles in the control of the actin cytoskeleton dynamics. Indicatively, Dictyostelium matches mammals in the number of these proteins. We give an overview of the Rho signalling pathways that regulate the actin dynamics in Dictyostelium and compare them with similar signalling networks in mammals. We also provide a phylogeny of Rho GTPases in Amoebozoa, which shows a variability of the Rho inventories across different clades found also in Metazoa.


2005 ◽  
Vol 72 ◽  
pp. 119-127 ◽  
Author(s):  
Tamara Golub ◽  
Caroni Pico

The interactions of cells with their environment involve regulated actin-based motility at defined positions along the cell surface. Sphingolipid- and cholesterol-dependent microdomains (rafts) order proteins at biological membranes, and have been implicated in most signalling processes at the cell surface. Many membrane-bound components that regulate actin cytoskeleton dynamics and cell-surface motility associate with PtdIns(4,5)P2-rich lipid rafts. Although raft integrity is not required for substrate-directed cell spreading, or to initiate signalling for motility, it is a prerequisite for sustained and organized motility. Plasmalemmal rafts redistribute rapidly in response to signals, triggering motility. This process involves the removal of rafts from sites that are not interacting with the substrate, apparently through endocytosis, and a local accumulation at sites of integrin-mediated substrate interactions. PtdIns(4,5)P2-rich lipid rafts can assemble into patches in a process depending on PtdIns(4,5)P2, Cdc42 (cell-division control 42), N-WASP (neural Wiskott-Aldrich syndrome protein) and actin cytoskeleton dynamics. The raft patches are sites of signal-induced actin assembly, and their accumulation locally promotes sustained motility. The patches capture microtubules, which promote patch clustering through PKA (protein kinase A), to steer motility. Raft accumulation at the cell surface, and its coupling to motility are influenced greatly by the expression of intrinsic raft-associated components that associate with the cytosolic leaflet of lipid rafts. Among them, GAP43 (growth-associated protein 43)-like proteins interact with PtdIns(4,5)P2 in a Ca2+/calmodulin and PKC (protein kinase C)-regulated manner, and function as intrinsic determinants of motility and anatomical plasticity. Plasmalemmal PtdIns(4,5)P2-rich raft assemblies thus provide powerful organizational principles for tight spatial and temporal control of signalling in motility.


Sign in / Sign up

Export Citation Format

Share Document