Profilin is required for posterior patterning of the Drosophila oocyte

Development ◽  
1996 ◽  
Vol 122 (7) ◽  
pp. 2109-2116 ◽  
Author(s):  
L. Manseau ◽  
J. Calley ◽  
H. Phan
Keyword(s):  
Actin Cytoskeleton ◽  
Cytoplasmic Streaming ◽  
Posterior Pole ◽  
Cytochalasin D ◽  
Actin Binding ◽  
Nurse Cells ◽  
Actin Binding Protein ◽  
Mutant Phenotypes ◽  
Two Hybrid

We have investigated the role of the actin cytoskeleton during mid-oogenesis and have found that disrupting the actin cytoskeleton with cytochalasin D induces microtubule bundling and microtubule-based cytoplasmic streaming within the oocyte, similar to that which occurs prematurely in cappuccino and spire mutant oocytes. After examining a number of mutants that affect the actin cytoskeleton, we have found that chickadee, which encodes the actin-binding protein, profilin, shares this phenotype. In addition to the microtubule misregulation, mutants in chickadee resemble cappuccino in that they fail to localize STAUFEN and oskar mRNA to the posterior pole of the developing oocyte. Also, a strong allele of cappuccino has multinucleate nurse cells, similar to those previously described in chickadee. In an independent line of experiments, we have identified profilin as a CAPPUCCINO interactor in a two-hybrid screen for proteins that bind to CAPPUCCINO. This, together with the similarity of mutant phenotypes, suggests that profilin and CAPPUCCINO may interact during development.

Clathrin Hub Expression Dissociates the Actin-Binding Protein Hip1R from Coated Pits and Disrupts Their Alignment with the Actin Cytoskeleton

Traffic ◽  
2001 ◽  
Vol 2 (11) ◽  
pp. 851-858 ◽  
Author(s):  
Elizabeth M. Bennett ◽  
Chih-Ying Chen ◽  
Asa E. Y. Engqvist-Goldstein ◽  
David G. Drubin ◽  
Frances M. Brodsky
Keyword(s):  
Actin Cytoskeleton ◽  
Binding Protein ◽  
Actin Binding ◽  
Coated Pits ◽  
Actin Binding Protein

scholarly journals Microtubule–microtubule sliding by kinesin-1 is essential for normal cytoplasmic streaming in Drosophila oocytes

2016 ◽  
Vol 113 (34) ◽  
pp. E4995-E5004 ◽  
Author(s):  
Wen Lu ◽  
Michael Winding ◽  
Margot Lakonishok ◽  
Jill Wildonger ◽  
Vladimir I. Gelfand
Keyword(s):  
Cytoplasmic Streaming ◽  
Cell Types ◽  
Nurse Cells ◽  
Wild Type ◽  
Actin Cortex ◽  
Microtubule Motor ◽  
Multiple Cell ◽  
Cytoplasmic Microtubules ◽  
Two Populations

Cytoplasmic streaming in Drosophila oocytes is a microtubule-based bulk cytoplasmic movement. Streaming efficiently circulates and localizes mRNAs and proteins deposited by the nurse cells across the oocyte. This movement is driven by kinesin-1, a major microtubule motor. Recently, we have shown that kinesin-1 heavy chain (KHC) can transport one microtubule on another microtubule, thus driving microtubule–microtubule sliding in multiple cell types. To study the role of microtubule sliding in oocyte cytoplasmic streaming, we used a Khc mutant that is deficient in microtubule sliding but able to transport a majority of cargoes. We demonstrated that streaming is reduced by genomic replacement of wild-type Khc with this sliding-deficient mutant. Streaming can be fully rescued by wild-type KHC and partially rescued by a chimeric motor that cannot move organelles but is active in microtubule sliding. Consistent with these data, we identified two populations of microtubules in fast-streaming oocytes: a network of stable microtubules anchored to the actin cortex and free cytoplasmic microtubules that moved in the ooplasm. We further demonstrated that the reduced streaming in sliding-deficient oocytes resulted in posterior determination defects. Together, we propose that kinesin-1 slides free cytoplasmic microtubules against cortically immobilized microtubules, generating forces that contribute to cytoplasmic streaming and are essential for the refinement of posterior determinants.

The role of plant villin in the organization of the actin cytoskeleton, cytoplasmic streaming and the architecture of the transvacuolar strand in root hair cells of Hydrocharis

Planta ◽  
2000 ◽  
Vol 210 (5) ◽  
pp. 836-843 ◽  
Author(s):  
Motoki Tominaga ◽  
Etsuo Yokota ◽  
Luis Vidali ◽  
Seiji Sonobe ◽  
Peter K. Hepler ◽  
...  
Keyword(s):  
Actin Cytoskeleton ◽  
Hair Cells ◽  
Root Hair ◽  
Cytoplasmic Streaming ◽  
Root Hair Cells

scholarly journals Bundling up the Role of the Actin Cytoskeleton in Primary Root Growth

2021 ◽  
Vol 12 ◽  
Author(s):  
Judith García-González ◽  
Kasper van Gelderen
Keyword(s):  
Root Growth ◽  
Actin Cytoskeleton ◽  
Cell Elongation ◽  
Feedback Loop ◽  
Primary Root ◽  
Actin Binding ◽  
Actin Network ◽  
Actin Organization ◽  
Primary Root Growth

Primary root growth is required by the plant to anchor in the soil and reach out for nutrients and water, while dealing with obstacles. Efficient root elongation and bending depends upon the coordinated action of environmental sensing, signal transduction, and growth responses. The actin cytoskeleton is a highly plastic network that constitutes a point of integration for environmental stimuli and hormonal pathways. In this review, we present a detailed compilation highlighting the importance of the actin cytoskeleton during primary root growth and we describe how actin-binding proteins, plant hormones, and actin-disrupting drugs affect root growth and root actin. We also discuss the feedback loop between actin and root responses to light and gravity. Actin affects cell division and elongation through the control of its own organization. We remark upon the importance of longitudinally oriented actin bundles as a hallmark of cell elongation as well as the role of the actin cytoskeleton in protein trafficking and vacuolar reshaping during this process. The actin network is shaped by a plethora of actin-binding proteins; however, there is still a large gap in connecting the molecular function of these proteins with their developmental effects. Here, we summarize their function and known effects on primary root growth with a focus on their high level of specialization. Light and gravity are key factors that help us understand root growth directionality. The response of the root to gravity relies on hormonal, particularly auxin, homeostasis, and the actin cytoskeleton. Actin is necessary for the perception of the gravity stimulus via the repositioning of sedimenting statoliths, but it is also involved in mediating the growth response via the trafficking of auxin transporters and cell elongation. Furthermore, auxin and auxin analogs can affect the composition of the actin network, indicating a potential feedback loop. Light, in its turn, affects actin organization and hence, root growth, although its precise role remains largely unknown. Recently, fundamental studies with the latest techniques have given us more in-depth knowledge of the role and organization of actin in the coordination of root growth; however, there remains a lot to discover, especially in how actin organization helps cell shaping, and therefore root growth.

scholarly journals Structure of Toxoplasma gondii coronin, an actin‐binding protein that relocalizes to the posterior pole of invasive parasites and contributes to invasion and egress

2014 ◽  
Vol 28 (11) ◽  
pp. 4729-4747 ◽  
Author(s):  
Julien Salamun ◽  
Juha P. Kallio ◽  
Wassim Daher ◽  
Dominique Soldati‐Favre ◽  
Inari Kursula
Keyword(s):  
Toxoplasma Gondii ◽  
Binding Protein ◽  
Posterior Pole ◽  
Actin Binding ◽  
Actin Binding Protein

scholarly journals α-Catenin-independent Recruitment of ZO-1 to Nectin-based Cell-Cell Adhesion Sites through Afadin

2001 ◽  
Vol 12 (6) ◽  
pp. 1595-1609 ◽  
Author(s):  
Shigekazu Yokoyama ◽  
Kouichi Tachibana ◽  
Hiroyuki Nakanishi ◽  
Yasunori Yamamoto ◽  
Kenji Irie ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Actin Cytoskeleton ◽  
Tight Junctions ◽  
Cell Lines ◽  
Adhesion Molecule ◽  
Binding Protein ◽  
Actin Binding ◽  
Actin Binding Protein ◽  
Adhesion Sites ◽  
Cell Cell

ZO-1 is an actin filament (F-actin)–binding protein that localizes to tight junctions and connects claudin to the actin cytoskeleton in epithelial cells. In nonepithelial cells that have no tight junctions, ZO-1 localizes to adherens junctions (AJs) and may connect cadherin to the actin cytoskeleton indirectly through β- and α-catenins as one of many F-actin–binding proteins. Nectin is an immunoglobulin-like adhesion molecule that localizes to AJs and is associated with the actin cytoskeleton through afadin, an F-actin–binding protein. Ponsin is an afadin- and vinculin-binding protein that also localizes to AJs. The nectin-afadin complex has a potency to recruit the E-cadherin–β-catenin complex through α-catenin in a manner independent of ponsin. By the use of cadherin-deficient L cell lines stably expressing various components of the cadherin-catenin and nectin-afadin systems, and α-catenin–deficient F9 cell lines, we examined here whether nectin recruits ZO-1 to nectin-based cell-cell adhesion sites. Nectin showed a potency to recruit not only α-catenin but also ZO-1 to nectin-based cell-cell adhesion sites. This recruitment of ZO-1 was dependent on afadin but independent of α-catenin and ponsin. These results indicate that ZO-1 localizes to cadherin-based AJs through interactions not only with α-catenin but also with the nectin-afadin system.

scholarly journals The Role of Protein Kinase C in the Transient Association of p57, a Coronin Family Actin-Binding Protein, with Phagosomes

2002 ◽  
Vol 25 (7) ◽  
pp. 837-844 ◽  
Author(s):  
Saotomo Itoh ◽  
Kensuke Suzuki ◽  
Jun Nishihata ◽  
Mitsusada Iwasa ◽  
Teruaki Oku ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Binding Protein ◽  
Actin Binding ◽  
Actin Binding Protein ◽  
Kinase C

scholarly journals Transfection of nonmuscle beta- and gamma-actin genes into myoblasts elicits different feedback regulatory responses from endogenous actin genes

1992 ◽  
Vol 117 (4) ◽  
pp. 787-797 ◽  
Author(s):  
C Lloyd ◽  
G Schevzov ◽  
P Gunning
Keyword(s):  
Actin Cytoskeleton ◽  
Feedback Regulation ◽  
Cytochalasin D ◽  
Actin Gene ◽  
Down Regulation ◽  
Actin Genes ◽  
Beta Actin ◽  
Actin Mrna ◽  
Actin Protein

We have examined the role of feedback-regulation in the expression of the nonmuscle actin genes. C2 mouse myoblasts were transfected with the human beta- and gamma-actin genes. In gamma-actin transfectants we found that the total actin mRNA and protein pools remained unchanged. Increasing levels of human gamma-actin expression resulted in a progressive down-regulation of mouse beta- and gamma-actin mRNAs. Transfection of the beta-actin gene resulted in an increase in the total actin mRNA and protein pools and induced an increase in the levels of mouse beta-actin mRNA. In contrast, transfection of a beta-actin gene carrying a single-point mutation (beta sm) produced a feedback-regulatory response similar to that of the gamma-actin gene. Expression of a beta-actin gene encoding an unstable actin protein had no impact on the endogenous mouse actin genes. This suggests that the nature of the encoded actin protein determines the feedback-regulatory response of the mouse genes. The role of the actin cytoskeleton in mediating this feedback-regulation was evaluated by disruption of the actin network with Cytochalasin D. We found that treatment with Cytochalasin D abolished the down-regulation of mouse gamma-actin in both the gamma- and beta sm-actin transfectants. In contrast, a similar level of increase was observed for the mouse beta-actin mRNA in both control and transfected cells. These experiments suggest that the down-regulation of mouse gamma-actin mRNA is dependent on the organization of the actin cytoskeleton. In addition, the mechanism responsible for the down-regulation of beta-actin may be distinct from that governing gamma-actin. We conclude that actin feedback-regulation provides a biochemical assay for differences between the two nonmuscle actin genes.

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