Non-centrosomal epidermal microtubules act in parallel to LET-502/ROCK to promote C. elegans elongation.
Development
; 143(1): 160-73, 2016 Jan 01.
Article
em En
| MEDLINE
| ID: mdl-26586219
ABSTRACT
C. elegans embryonic elongation is a morphogenetic event driven by actomyosin contractility and muscle-induced tension transmitted through hemidesmosomes. A role for the microtubule cytoskeleton has also been proposed, but its contribution remains poorly characterized. Here, we investigate the organization of the non-centrosomal microtubule arrays present in the epidermis and assess their function in elongation. We show that the microtubule regulators γ-tubulin and NOCA-1 are recruited to hemidesmosomes and adherens junctions early in elongation. Several parallel approaches suggest that microtubule nucleation occurs from these sites. Disrupting the epidermal microtubule array by overexpressing the microtubule-severing protein Spastin or by inhibiting the C. elegans ninein homolog NOCA-1 in the epidermis mildly affected elongation. However, microtubules were essential for elongation when hemidesmosomes or the activity of the Rho kinase LET-502/ROCK were partially compromised. Imaging of junctional components and genetic analyses suggest that epidermal microtubules function together with Rho kinase to promote the transport of E-cadherin to adherens junctions and myotactin to hemidesmosomes. Our results indicate that the role of LET-502 in junctional remodeling is likely to be independent of its established function as a myosin II activator, but requires a microtubule-dependent pathway involving the syntaxin SYX-5. Hence, we propose that non-centrosomal microtubules organized by epidermal junctions contribute to elongation by transporting junction remodeling factors, rather than having a mechanical role.
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01-internacional
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MEDLINE
Assunto principal:
Caenorhabditis elegans
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Proteínas de Caenorhabditis elegans
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Quinases Associadas a rho
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Células Epidérmicas
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Microtúbulos
Limite:
Animals
Idioma:
En
Ano de publicação:
2016
Tipo de documento:
Article