Myosin-5, kinesin-1 and myosin-17 cooperate in secretion of fungal chitin synthase.
EMBO J
; 31(1): 214-27, 2012 Jan 04.
Article
em En
| MEDLINE
| ID: mdl-22027862
ABSTRACT
Plant infection by pathogenic fungi requires polarized secretion of enzymes, but little is known about the delivery pathways. Here, we investigate the secretion of cell wall-forming chitin synthases (CHSs) in the corn pathogen Ustilago maydis. We show that peripheral filamentous actin (F-actin) and central microtubules (MTs) form independent tracks for CHSs delivery and both cooperate in cell morphogenesis. The enzyme Mcs1, a CHS that contains a myosin-17 motor domain, is travelling along both MTs and F-actin. This transport is independent of kinesin-3, but mediated by kinesin-1 and myosin-5. Arriving vesicles pause beneath the plasma membrane, but only ~15% of them get exocytosed and the majority is returned to the cell centre by the motor dynein. Successful exocytosis at the cell tip and, to a lesser extent at the lateral parts of the cell requires the motor domain of Mcs1, which captures and tethers the vesicles prior to secretion. Consistently, Mcs1-bound vesicles transiently bind F-actin but show no motility in vitro. Thus, kinesin-1, myosin-5 and dynein mediate bi-directional motility, whereas myosin-17 introduces a symmetry break that allows polarized secretion.
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Ustilago
/
Proteínas Fúngicas
/
Quitina Sintase
/
Miosinas
/
Cinesinas
Idioma:
En
Ano de publicação:
2012
Tipo de documento:
Article