scholarly journals Actin-binding protein G (AbpG) participates in modulating the actin cytoskeleton and cell migration in Dictyostelium discoideum

2015 ◽  
Vol 26 (6) ◽  
pp. 1084-1097 ◽  
Author(s):  
Wei-Chi Lin ◽  
Liang-Chen Wang ◽  
Te-Ling Pang ◽  
Mei-Yu Chen
Keyword(s):  
Cell Migration ◽  
Dictyostelium Discoideum ◽  
Molecular Mechanisms ◽  
Binding Protein ◽  
Protein Domain ◽  
Actin Dynamics ◽  
Actin Binding ◽  
Protein G ◽  
Wild Type ◽  
Actin Binding Protein

Cell migration is involved in various physiological and pathogenic events, and the complex underlying molecular mechanisms have not been fully elucidated. The simple eukaryote Dictyostelium discoideum displays chemotactic locomotion in stages of its life cycle. By characterizing a Dictyostelium mutant defective in chemotactic responses, we identified a novel actin-binding protein serving to modulate cell migration and named it actin-binding protein G (AbpG); this 971–amino acid (aa) protein contains an N-terminal type 2 calponin homology (CH2) domain followed by two large coiled-coil regions. In chemoattractant gradients, abpG− cells display normal directional persistence but migrate significantly more slowly than wild-type cells; expressing Flag-AbpG in mutant cells eliminates the motility defect. AbpG is enriched in cortical/lamellipodial regions and colocalizes well with F-actin; aa 401–600 and aa 501–550 fragments of AbpG show the same distribution as full-length AbpG. The aa 501–550 region of AbpG, which is essential for AbpG to localize to lamellipodia and to rescue the phenotype of abpG− cells, is sufficient for binding to F-actin and represents a novel actin-binding protein domain. Compared with wild-type cells, abpG− cells have significantly higher F-actin levels. Collectively our results suggest that AbpG may participate in modulating actin dynamics to optimize cell locomotion.

scholarly journals The Actin-Binding Protein UNC-115/abLIM Controls Formation of Lamellipodia and Filopodia and Neuronal Morphogenesis in Caenorhabditis elegans

2005 ◽  
Vol 25 (12) ◽  
pp. 5158-5170 ◽  
Author(s):  
Yieyie Yang ◽  
Erik A. Lundquist
Keyword(s):  
Caenorhabditis Elegans ◽  
Molecular Mechanisms ◽  
Binding Protein ◽  
Phosphorylation Site ◽  
Serine Phosphorylation ◽  
Actin Binding ◽  
Axon Pathfinding ◽  
Neuronal Morphogenesis ◽  
Actin Binding Protein ◽  
C Elegans

ABSTRACT The roles of actin-binding proteins in development and morphogenesis are not well understood. The actin-binding protein UNC-115 has been implicated in cytoskeletal signaling downstream of Rac in Caenorhabditis elegans axon pathfinding, but the cellular role of UNC-115 in this process remains undefined. Here we report that UNC-115 overactivity in C. elegans neurons promotes the formation of neurites and lamellipodial and filopodial extensions similar to those induced by activated Rac and normally found in C. elegans growth cones. We show that UNC-115 activity in neuronal morphogenesis is enhanced by two molecular mechanisms: when ectopically driven to the plasma membrane by the myristoylation sequence of c-Src, and by mutation of a putative serine phosphorylation site in the actin-binding domain of UNC-115. In support of the hypothesis that UNC-115 modulates actin cytoskeletal organization, we show that UNC-115 activity in serum-starved NIH 3T3 fibroblasts results in the formation of lamellipodia and filopodia. We conclude that UNC-115 is a novel regulator of the formation of lamellipodia and filopodia in neurons, possibly in the growth cone during axon pathfinding.

Proteomic profiling reveals that EhPC4 transcription factor induces cell migration through up-regulation of the 16-kDa actin-binding protein EhABP16 in Entamoeba histolytica

2014 ◽  
Vol 111 ◽  
pp. 46-58 ◽  
Author(s):  
Olga Hernández de la Cruz ◽  
Marcos Muñiz-Lino ◽  
Nancy Guillén ◽  
Christian Weber ◽  
Laurence A. Marchat ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Cell Migration ◽  
Entamoeba Histolytica ◽  
Binding Protein ◽  
Actin Binding ◽  
Proteomic Profiling ◽  
Actin Binding Protein

scholarly journals AIM1 is an actin-binding protein that suppresses cell migration and micrometastatic dissemination

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Michael C. Haffner ◽  
David M. Esopi ◽  
Alcides Chaux ◽  
Meltem Gürel ◽  
Susmita Ghosh ◽  
...  
Keyword(s):  
Cell Migration ◽  
Binding Protein ◽  
Actin Binding ◽  
Actin Binding Protein

scholarly journals Receptor Tyrosine Kinase Ror2 Mediates Wnt5a-induced Polarized Cell Migration by Activating c-Jun N-terminal Kinase via Actin-binding Protein Filamin A

2008 ◽  
Vol 283 (41) ◽  
pp. 27973-27981 ◽  
Author(s):  
Akira Nomachi ◽  
Michiru Nishita ◽  
Daisuke Inaba ◽  
Masahiro Enomoto ◽  
Mayumi Hamasaki ◽  
...  
Keyword(s):  
Cell Migration ◽  
Tyrosine Kinase ◽  
Receptor Tyrosine Kinase ◽  
Binding Protein ◽  
Actin Binding ◽  
Filamin A ◽  
Actin Binding Protein

scholarly journals αII-Spectrin interacts with Tes and EVL, two actin-binding proteins located at cell contacts

2005 ◽  
Vol 388 (2) ◽  
pp. 631-638 ◽  
Author(s):  
Björn ROTTER ◽  
Odile BOURNIER ◽  
Gael NICOLAS ◽  
Didier DHERMY ◽  
Marie-Christine LECOMTE
Keyword(s):  
Binding Protein ◽  
Focal Adhesions ◽  
Membrane Skeleton ◽  
Actin Dynamics ◽  
Actin Binding ◽  
Actin Binding Protein ◽  
Src Homology 3 ◽  
Src Homology 3 Domain ◽  
Src Homology

The spectrin-based membrane skeleton, a multi-protein scaffold attached to diverse cellular membranes, is presumed to be involved in the stabilization of membranes, the establishment of membrane domains as well as in vesicle trafficking and nuclear functions. Spectrin tetramers made of α- and β-subunits are linked to actin microfilaments, forming a network that binds a multitude of proteins. The most prevalent α-spectrin subunit in non-erythroid cells, αII-spectrin, contains two particular spectrin repeats in its central region, α9 and α10, which host an Src homology 3 domain, a tissue-specific spliced sequence of 20 residues, a calmodulin-binding site and major cleavage sites for caspases and calpains. Using yeast two-hybrid screening of kidney libraries, we identified two partners of the α9-α10 repeats: the potential tumour suppressor Tes, an actin-binding protein mainly located at focal adhesions; and EVL (Ena/vasodilator-stimulated phosphoprotein-like protein), another actin-binding protein, equally recruited at focal adhesions. Interactions between spectrin and overexpressed Tes and EVL were confirmed by co-immunoprecipitation. In vitro studies showed that the interaction between Tes and spectrin is mediated by a LIM (Lin-11, Isl-1 and Mec3) domain of Tes and by the α10 repeat of αII-spectrin whereas EVL interacts with the Src homology 3 domain located within the α9 repeat. Moreover, we describe an in vitro interaction between Tes and EVL, and a co-localization of these two proteins at focal adhesions. These interactions between αII-spectrin, Tes and EVL indicate new functions for spectrin in actin dynamics and focal adhesions.

scholarly journals Mapping actin surfaces required for functional interactions in vivo.

1994 ◽  
Vol 126 (2) ◽  
pp. 423-432 ◽  
Author(s):  
D A Holtzman ◽  
K F Wertman ◽  
D G Drubin
Keyword(s):  
Binding Protein ◽  
Null Alleles ◽  
Actin Binding ◽  
Null Mutation ◽  
Wild Type ◽  
Actin Binding Protein ◽  
Functional Interactions ◽  
Type Gene ◽  
First Time

An in vivo strategy to identify amino acids of actin required for functional interactions with actin-binding proteins was developed. This approach is based on the assumption that an actin mutation that specifically impairs the interaction with an actin-binding protein will cause a phenotype similar to a null mutation in the gene that encodes the actin-binding protein. 21 actin mutations were analyzed in budding yeast, and specific regions of actin subdomain 1 were implicated in the interaction with fimbrin, an actin filament-bundling protein. Mutations in this actin subdomain were shown to be, like a null allele of the yeast fimbrin gene (SAC6), lethal in combination with null mutations in the ABP1 and SLA2 genes, and viable in combination with a null mutation in the SLA1 gene. Biochemical experiments with act1-120 actin (E99A, E100A) verified a defect in the fimbrin-actin interaction. Genetic interactions between mutant alleles of the yeast actin gene and null alleles of the SAC6, ABP1, SLA1, and SLA2 genes also demonstrated that the effects of the 21 actin mutations are diverse and allowed four out of seven pseudo-wild-type actin alleles to be distinguished from the wild-type gene for the first time, providing evidence for functional redundancy between different surfaces of actin.

Regulation of the gene encoding the p24 actin-binding protein in Dictyostelium discoideum

1992 ◽  
Vol 70 (10-11) ◽  
pp. 1047-1054 ◽  
Author(s):  
Michael T. Greenwood ◽  
Adrian Tsang
Keyword(s):  
Dictyostelium Discoideum ◽  
Early Development ◽  
Binding Protein ◽  
Actin Binding ◽  
Protein Synthesis Inhibitor ◽  
Predicted Amino Acid Sequence ◽  
Cdna Clones ◽  
Mrna Levels ◽  
Gene Encoding ◽  
Actin Binding Protein

We have isolated cDNA clones on the basis of sequence similarity to the gene encoding the cyclic cAMP-binding protein CABP1 of Dictyostelium discoideum. The predicted amino acid sequence of the cloned cDNAs shows that the homology to CABP1 is restricted to a region rich in proline, glycine, glutamine, and tyrosine. Sequence comparison indicates that the cloned cDNAs encode the actin-binding protein p24. We have examined by RNA blot hybridization the expression of the gene encoding p24. For cells developed in suspension, the levels of p24 mRNA increase rapidly during early development, reaching a peak at 3–4 h. Addition of high concentrations of exogenous cAMP during the first 4 h of development produced little or no effect on the accumulation of p24 mRNA. Treatment with cAMP during subsequent stages of development reduced the levels of p24 mRNA. We attempted to determine if the synthesis of new proteins during early development is a requirement for the reduction in p24 mRNA levels by treating the cells with protein synthesis inhibitor. Unexpectedly, the addition of the inhibitor cycloheximide resulted in an increase in the level of p24 mRNA. The roles of cycloheximide and cAMP on the expression of the p24 gene are discussed.Key words: Dictyostelium discoideum, actin-binding protein, gene regulation, cAMP, cycloheximide.

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