scholarly journals Pan1p, End3p, and Sla1p, Three Yeast Proteins Required for Normal Cortical Actin Cytoskeleton Organization, Associate with Each Other and Play Essential Roles in Cell Wall Morphogenesis

2000 ◽  
Vol 20 (1) ◽  
pp. 12-25 ◽  
Author(s):  
Hsin-Yao Tang ◽  
Jing Xu ◽  
Mingjie Cai
Keyword(s):  
Cell Wall ◽  
Actin Cytoskeleton ◽  
Normal Cell ◽  
Cell Cortex ◽  
Repeat Region ◽  
Cortical Actin ◽  
Cytoskeleton Organization ◽  
Eh Domain ◽  
Actin Cytoskeleton Organization ◽  
Cell Wall Morphogenesis

ABSTRACT The EH domain proteins Pan1p and End3p of budding yeast have been known to form a complex in vivo and play important roles in organization of the actin cytoskeleton and endocytosis. In this report, we describe new findings concerning the function of the Pan1p-End3p complex. First, we found that the Pan1p-End3p complex associates with Sla1p, another protein known to be required for the assembly of cortical actin structures. Sla1p interacts with the first long repeat region of Pan1p and the N-terminal EH domain of End3p, thus leaving the Pan1p-End3p interaction, which requires the second long repeat of Pan1p and the C-terminal repeat region of End3p, undisturbed. Second, Pan1p, End3p, and Sla1p are also required for normal cell wall morphogenesis. Each of the Pan1-4, sla1Δ, andend3Δ mutants displays the abnormal cell wall morphology previously reported for the act1-1 mutant. These cell wall defects are also exhibited by wild-type cells overproducing the C-terminal region of Sla1p that is responsible for interactions with Pan1p and End3p. These results indicate that the functions of Pan1p, End3p, and Sla1p in cell wall morphogenesis may depend on the formation of a heterotrimeric complex. Interestingly, the cell wall abnormalities exhibited by these cells are independent of the actin cytoskeleton organization on the cell cortex, as they manifest despite the presence of apparently normal cortical actin cytoskeleton. Examination of several act1 mutants also supports this conclusion. These observations suggest that the Pan1p-End3p-Sla1p complex is required not only for normal actin cytoskeleton organization but also for normal cell wall morphogenesis in yeast.

scholarly journals Golgi Body Motility in the Plant Cell Cortex Correlates with Actin Cytoskeleton Organization

2011 ◽  
Vol 52 (10) ◽  
pp. 1844-1855 ◽  
Author(s):  
Miriam Akkerman ◽  
Elysa J. R. Overdijk ◽  
Jan H. N. Schel ◽  
Anne Mie C. Emons ◽  
Tijs Ketelaar
Keyword(s):  
Actin Cytoskeleton ◽  
Plant Cell ◽  
Golgi Body ◽  
Cell Cortex ◽  
Cytoskeleton Organization ◽  
Actin Cytoskeleton Organization ◽  
Body Motility

scholarly journals Yeast actin cytoskeleton mutants accumulate a new class of Golgi-derived secretary vesicle.

1997 ◽  
Vol 8 (8) ◽  
pp. 1481-1499 ◽  
Author(s):  
J Mulholland ◽  
A Wesp ◽  
H Riezman ◽  
D Botstein
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Actin Cytoskeleton ◽  
Biochemical Analysis ◽  
Small Gtpase ◽  
Secretory Vesicles ◽  
Cytoskeleton Organization ◽  
New Class ◽  
Actin Cytoskeleton Organization ◽  
Vectorial Transport

Many yeast actin cytoskeleton mutants accumulate large secretory vesicles and exhibit phenotypes consistent with defects in polarized growth. This, together with actin's polarized organization, has suggested a role for the actin cytoskeleton in the vectorial transport of late secretory vesicles to the plasma membrane. By using ultrastructural and biochemical analysis, we have characterized defects manifested by mutations in the SLA2 gene (also known as the END4 gene), previously found to affect both the organization of the actin cytoskeleton and endocytosis in yeast. Defects in cell wall morphology, accumulated vesicles, and protein secretion kinetics were found in sla2 mutants similar to defects found in act1 mutants. Vesicles that accumulate in the sla2 and act1 mutants are immunoreactive with antibodies directed against the small GTPase Ypt1p but not with antibodies directed against the homologous Sec4p found on classical "late" secretory vesicles. In contrast, the late-acting secretory mutants sec1-1 and sec6-4 are shown to accumulate anti-Sec4p-positive secretory vesicles as well as vesicles that are immunoreactive with antibodies directed against Ypt1p. The late sec mutant sec4-8 is also shown to accumulate Ypt1p-containing vesicles and to exhibit defects in actin cytoskeleton organization. These results indicate the existence of at least two classes of morphologically similar, late secretory vesicles (associated with Ypt1p+ and Sec4p+, respectively), one of which appears to accumulate when the actin cytoskeleton is disorganized.

scholarly journals EH domain proteins Pan1p and End3p are components of a complex that plays a dual role in organization of the cortical actin cytoskeleton and endocytosis in Saccharomyces cerevisiae.

1997 ◽  
Vol 17 (8) ◽  
pp. 4294-4304 ◽  
Author(s):  
H Y Tang ◽  
A Munn ◽  
M Cai
Keyword(s):  
Actin Cytoskeleton ◽  
Growth Factor Receptor ◽  
Cell Cortex ◽  
Restrictive Temperature ◽  
Permissive Temperature ◽  
Cortical Actin ◽  
Kinase Substrate ◽  
Physiological Relevance ◽  
Eh Domain

Several proteins from diverse organisms have been shown to share a region of sequence homology with the mammalian epidermal growth factor receptor tyrosine kinase substrate Eps15. Included in this new protein family, termed EH domain proteins, are two yeast proteins, Pan1p and End3p. We have shown previously that Pan1p is required for normal organization of the actin cytoskeleton and that it associates with the actin patches on the cell cortex. End3p has been shown by others to be an important factor in the process of endocytosis. End3p is also known to be required for the organization of the actin cytoskeleton. Here we report that Pan1p and End3p act as a complex in vivo. Using the pan1-4 mutant which we isolated and characterized previously, the END3 gene was identified as a suppressor of pan1-4 when overexpressed. Suppression of the pan1-4 mutation by multicopy END3 required the presence of the mutant Pan1p protein. Coimmunoprecipitation and two-hybrid protein interaction experiments indicated that Pan1p and End3p associate with each other. The localization of Pan1p to the cortical actin cytoskeleton became weakened in the end3 mutant at the permissive temperature and undetectable at the restrictive temperature, suggesting that End3p may be important for proper localization of Pan1p to the cortical actin cytoskeleton. The finding that the pan1-4 mutant was defective in endocytosis as severely as the end3 mutant under nonpermissive conditions supports the notion that the association between Pan1p and End3p is of physiological relevance. Together with results of earlier reports, these results provide strong evidence suggesting that Pan1p and End3p are the components of a complex that has essential functions in both the organization of cell membrane-associated actin cytoskeleton and the process of endocytosis.

A novel EH domain protein of Saccharomyces cerevisiae, Ede1p, involved in endocytosis

2000 ◽  
Vol 113 (18) ◽  
pp. 3309-3319 ◽  
Author(s):  
B. Gagny ◽  
A. Wiederkehr ◽  
P. Dumoulin ◽  
B. Winsor ◽  
H. Riezman ◽  
...  
Keyword(s):  
Fluorescent Protein ◽  
Genetic Interaction ◽  
Fluid Phase ◽  
Cortical Actin ◽  
Entire Genome ◽  
Functional Link ◽  
Cytoskeleton Organization ◽  
Eh Domain ◽  
Actin Cytoskeleton Organization ◽  
Green Fluorescent

Sequencing of the entire genome of S. cerevisiae has revealed the existence of five proteins containing EH domains. These are protein-protein interaction modules first described in mammalian Eps15, a protein that is involved in clathrin-dependent endocytosis. Two of the yeast proteins, End3p and Pan1p, are required for the internalization step of endocytosis. We report characterization of the nonessential ORF YBL047c which, like Eps15, encodes a protein with three N-terminal EH domains. Deletion of YBL047c leads to a defective fluid-phase endocytosis and to defective internalization of the pheromone (alpha)-factor and uracil permease. We therefore named YBL047c EDE1, for EH Domains and Endocytosis. Ede1p expressed as a chromosomally encoded fusion to the green fluorescent protein is localized in punctate cortical spots that only partially colocalize with actin patches. This localization is maintained when actin is depolymerized. Deletion of EDE1 impairs the diploid budding pattern, but has only a small impact on actin cytoskeleton organization, in contrast to the effects observed in pan1 cells and many end mutants impaired in proteins colocalizing with cortical actin patches. Genetic interaction was observed between EDE1 and RSP5, which encodes the ubiquitin ligase Rsp5p essential for ubiquitin-dependent endocytosis of many plasma membrane proteins, thus further emphasizing the functional link between Rsp5p and the EH domain proteins. We also observed genetic interaction between EDE1, and END3 or PAN1, suggesting that Ede1p might be part of a yeast EH network implicated in endocytosis.

scholarly journals TheSaccharomyces cerevisiae14-3-3 Proteins Are Required for the G1/S Transition, Actin Cytoskeleton Organization and Cell Wall Integrity

Genetics ◽  
2006 ◽  
Vol 173 (2) ◽  
pp. 661-675 ◽  
Author(s):  
Francisca Lottersberger ◽  
Andrea Panza ◽  
Giovanna Lucchini ◽  
Simonetta Piatti ◽  
Maria Pia Longhese
Keyword(s):  
Cell Wall ◽  
Actin Cytoskeleton ◽  
Cell Wall Integrity ◽  
Cytoskeleton Organization ◽  
Actin Cytoskeleton Organization

The actin cytoskeleton is required to elaborate and maintain spatial patterning during trichome cell morphogenesis in Arabidopsis thaliana

Development ◽  
1999 ◽  
Vol 126 (24) ◽  
pp. 5559-5568 ◽  
Author(s):  
J. Mathur ◽  
P. Spielhofer ◽  
B. Kost ◽  
N. Chua
Keyword(s):  
Arabidopsis Thaliana ◽  
Actin Cytoskeleton ◽  
Spatial Patterning ◽  
Actin Microfilaments ◽  
Cell Morphogenesis ◽  
Actin Organization ◽  
Cytoskeleton Organization ◽  
Branch Formation ◽  
Actin Cytoskeleton Organization ◽  
Trichome Cell

Arabidopsis thaliana trichomes provide an attractive model system to dissect molecular processes involved in the generation of shape and form in single cell morphogenesis in plants. We have used transgenic Arabidopsis plants carrying a GFP-talin chimeric gene to analyze the role of the actin cytoskeleton in trichome cell morphogenesis. We found that during trichome cell development the actin microfilaments assumed an increasing degree of complexity from fine filaments to thick, longitudinally stretched cables. Disruption of the F-actin cytoskeleton by actin antagonists produced distorted but branched trichomes which phenocopied trichomes of mutants belonging to the ‘distorted’ class. Subsequent analysis of the actin cytoskeleton in trichomes of the distorted mutants, alien, crooked, distorted1, gnarled, klunker and wurm uncovered actin organization defects in each case. Treatments of wild-type seedlings with microtubule-interacting drugs elicited a radically different trichome phenotype characterized by isotropic growth and a severe inhibition of branch formation; these trichomes did not show defects in actin cytoskeleton organization. A normal actin cytoskeleton was also observed in trichomes of the zwichel mutant which have reduced branching. ZWICHEL, which was previously shown to encode a kinesin-like protein is thought to be involved in microtubule-linked processes. Based on our results we propose that microtubules establish the spatial patterning of trichome branches whilst actin microfilaments elaborate and maintain the overall trichome pattern during development.

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