The V-ATPase accessory protein Atp6ap1b mediates dorsal forerunner cell proliferation and left-right asymmetry in zebrafish.
Dev Biol
; 407(1): 115-30, 2015 Nov 01.
Article
em En
| MEDLINE
| ID: mdl-26254189
ABSTRACT
Asymmetric fluid flows generated by motile cilia in a transient 'organ of asymmetry' are involved in establishing the left-right (LR) body axis during embryonic development. The vacuolar-type H(+)-ATPase (V-ATPase) proton pump has been identified as an early factor in the LR pathway that functions prior to cilia, but the role(s) for V-ATPase activity are not fully understood. In the zebrafish embryo, the V-ATPase accessory protein Atp6ap1b is maternally supplied and expressed in dorsal forerunner cells (DFCs) that give rise to the ciliated organ of asymmetry called Kupffer's vesicle (KV). V-ATPase accessory proteins modulate V-ATPase activity, but little is known about their functions in development. We investigated Atp6ap1b and V-ATPase in KV development using morpholinos, mutants and pharmacological inhibitors. Depletion of both maternal and zygotic atp6ap1b expression reduced KV organ size, altered cilia length and disrupted LR patterning of the embryo. Defects in other ciliated structures-neuromasts and olfactory placodes-suggested a broad role for Atp6ap1b during development of ciliated organs. V-ATPase inhibitor treatments reduced KV size and identified a window of development in which V-ATPase activity is required for proper LR asymmetry. Interfering with Atp6ap1b or V-ATPase function reduced the rate of DFC proliferation, which resulted in fewer ciliated cells incorporating into the KV organ. Analyses of pH and subcellular V-ATPase localizations suggested Atp6ap1b functions to localize the V-ATPase to the plasma membrane where it regulates proton flux and cytoplasmic pH. These results uncover a new role for the V-ATPase accessory protein Atp6ap1b in early development to maintain the proliferation rate of precursor cells needed to construct a ciliated KV organ capable of generating LR asymmetry.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Peixe-Zebra
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Cílios
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ATPases Translocadoras de Prótons
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Padronização Corporal
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Proteínas de Peixe-Zebra
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Proliferação de Células
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Dev Biol
Ano de publicação:
2015
Tipo de documento:
Article
País de afiliação:
Estados Unidos