Dynamics of the actin cytoskeleton in Phytophthora infestans hyphae and infection structures

Research output: Chapter in Book/Report/Conference proceedingAbstract

Abstract

The actin cytoskeleton is a dynamic but well organized intracellular framework that is indispensable for the viability of eukaryotic cells. Its functions range from intracellular transport, formation of contractile rings, nuclear segregation, endocytosis and facilitating apical cell expansions. We studied the actin cytoskeleton dynamics in the filamentous oomycete plant pathogen Phytophthora infestans in transgenic lines expressing the actin binding peptide Lifeact-eGFP by fluorescence microscopy. This showed that in hyphae actin filament cables and plaques are cortically localized. The distance between the hyphal tip and the first actin filament plaque correlated strongly with growth velocity. Upon growth termination, actin filament plaques appeared in the hyphal tip. The plaques were nearly immobile with average lifetimes exceeding one hour; much longer (over 500-fold) than the lifetimes of actin patches in fungi. Plaque assembly required ~30 seconds while disassembly took only ~10 seconds. In contrast to actin patches in yeast, plaque disassembly was not accompanied with formation and internalization of endocytic vesicles (Meijer et al. 2014, Cell. Microbiol.). We also investigated the in vivo actin dynamics during early stages of pathogenesis. At the site of contact with the plant cell a condensed transient actin structure was observed that resembles aster-like actin structures formed upon encountering hard surfaces. Our results suggest that the actin cytoskeleton has distinct functions during the P. infestans lifecycle. Future efforts will focus at identifying interactors and key regulators of the actin cytoskeleton and pinpoint features in the actin network that are unique for oomycetes.
Original languageEnglish
Title of host publicationBook of Abstracts 28th Fungal Genetics Conference
Pages30
Publication statusPublished - 2015
Event28th Fungal Genetics Conference, Pacific Grove, CA, USA -
Duration: 17 Mar 201522 Mar 2015

Conference

Conference28th Fungal Genetics Conference, Pacific Grove, CA, USA
Period17/03/1522/03/15

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Phytophthora infestans
Hyphae
Actin Cytoskeleton
Actins
Infection
Oomycetes
Transport Vesicles
Plant Cells
Eukaryotic Cells
Growth
Endocytosis
Fluorescence Microscopy
Fungi
Yeasts
Peptides

Cite this

Meijer, H. J. G., Kots, K., Hua, C., Ketelaar, T., & Govers, F. (2015). Dynamics of the actin cytoskeleton in Phytophthora infestans hyphae and infection structures. In Book of Abstracts 28th Fungal Genetics Conference (pp. 30)
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abstract = "The actin cytoskeleton is a dynamic but well organized intracellular framework that is indispensable for the viability of eukaryotic cells. Its functions range from intracellular transport, formation of contractile rings, nuclear segregation, endocytosis and facilitating apical cell expansions. We studied the actin cytoskeleton dynamics in the filamentous oomycete plant pathogen Phytophthora infestans in transgenic lines expressing the actin binding peptide Lifeact-eGFP by fluorescence microscopy. This showed that in hyphae actin filament cables and plaques are cortically localized. The distance between the hyphal tip and the first actin filament plaque correlated strongly with growth velocity. Upon growth termination, actin filament plaques appeared in the hyphal tip. The plaques were nearly immobile with average lifetimes exceeding one hour; much longer (over 500-fold) than the lifetimes of actin patches in fungi. Plaque assembly required ~30 seconds while disassembly took only ~10 seconds. In contrast to actin patches in yeast, plaque disassembly was not accompanied with formation and internalization of endocytic vesicles (Meijer et al. 2014, Cell. Microbiol.). We also investigated the in vivo actin dynamics during early stages of pathogenesis. At the site of contact with the plant cell a condensed transient actin structure was observed that resembles aster-like actin structures formed upon encountering hard surfaces. Our results suggest that the actin cytoskeleton has distinct functions during the P. infestans lifecycle. Future efforts will focus at identifying interactors and key regulators of the actin cytoskeleton and pinpoint features in the actin network that are unique for oomycetes.",
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Meijer, HJG, Kots, K, Hua, C, Ketelaar, T & Govers, F 2015, Dynamics of the actin cytoskeleton in Phytophthora infestans hyphae and infection structures. in Book of Abstracts 28th Fungal Genetics Conference. pp. 30, 28th Fungal Genetics Conference, Pacific Grove, CA, USA, 17/03/15.

Dynamics of the actin cytoskeleton in Phytophthora infestans hyphae and infection structures. / Meijer, H.J.G.; Kots, K.; Hua, C.; Ketelaar, T.; Govers, F.

Book of Abstracts 28th Fungal Genetics Conference. 2015. p. 30.

Research output: Chapter in Book/Report/Conference proceedingAbstract

TY - CHAP

T1 - Dynamics of the actin cytoskeleton in Phytophthora infestans hyphae and infection structures

AU - Meijer, H.J.G.

AU - Kots, K.

AU - Hua, C.

AU - Ketelaar, T.

AU - Govers, F.

PY - 2015

Y1 - 2015

N2 - The actin cytoskeleton is a dynamic but well organized intracellular framework that is indispensable for the viability of eukaryotic cells. Its functions range from intracellular transport, formation of contractile rings, nuclear segregation, endocytosis and facilitating apical cell expansions. We studied the actin cytoskeleton dynamics in the filamentous oomycete plant pathogen Phytophthora infestans in transgenic lines expressing the actin binding peptide Lifeact-eGFP by fluorescence microscopy. This showed that in hyphae actin filament cables and plaques are cortically localized. The distance between the hyphal tip and the first actin filament plaque correlated strongly with growth velocity. Upon growth termination, actin filament plaques appeared in the hyphal tip. The plaques were nearly immobile with average lifetimes exceeding one hour; much longer (over 500-fold) than the lifetimes of actin patches in fungi. Plaque assembly required ~30 seconds while disassembly took only ~10 seconds. In contrast to actin patches in yeast, plaque disassembly was not accompanied with formation and internalization of endocytic vesicles (Meijer et al. 2014, Cell. Microbiol.). We also investigated the in vivo actin dynamics during early stages of pathogenesis. At the site of contact with the plant cell a condensed transient actin structure was observed that resembles aster-like actin structures formed upon encountering hard surfaces. Our results suggest that the actin cytoskeleton has distinct functions during the P. infestans lifecycle. Future efforts will focus at identifying interactors and key regulators of the actin cytoskeleton and pinpoint features in the actin network that are unique for oomycetes.

AB - The actin cytoskeleton is a dynamic but well organized intracellular framework that is indispensable for the viability of eukaryotic cells. Its functions range from intracellular transport, formation of contractile rings, nuclear segregation, endocytosis and facilitating apical cell expansions. We studied the actin cytoskeleton dynamics in the filamentous oomycete plant pathogen Phytophthora infestans in transgenic lines expressing the actin binding peptide Lifeact-eGFP by fluorescence microscopy. This showed that in hyphae actin filament cables and plaques are cortically localized. The distance between the hyphal tip and the first actin filament plaque correlated strongly with growth velocity. Upon growth termination, actin filament plaques appeared in the hyphal tip. The plaques were nearly immobile with average lifetimes exceeding one hour; much longer (over 500-fold) than the lifetimes of actin patches in fungi. Plaque assembly required ~30 seconds while disassembly took only ~10 seconds. In contrast to actin patches in yeast, plaque disassembly was not accompanied with formation and internalization of endocytic vesicles (Meijer et al. 2014, Cell. Microbiol.). We also investigated the in vivo actin dynamics during early stages of pathogenesis. At the site of contact with the plant cell a condensed transient actin structure was observed that resembles aster-like actin structures formed upon encountering hard surfaces. Our results suggest that the actin cytoskeleton has distinct functions during the P. infestans lifecycle. Future efforts will focus at identifying interactors and key regulators of the actin cytoskeleton and pinpoint features in the actin network that are unique for oomycetes.

M3 - Abstract

SP - 30

BT - Book of Abstracts 28th Fungal Genetics Conference

ER -

Meijer HJG, Kots K, Hua C, Ketelaar T, Govers F. Dynamics of the actin cytoskeleton in Phytophthora infestans hyphae and infection structures. In Book of Abstracts 28th Fungal Genetics Conference. 2015. p. 30