CIBICI   14215
CENTRO DE INVESTIGACION EN BIOQUIMICA CLINICA E INMUNOLOGIA
Unidad Ejecutora - UE
artículos
Título:
Identifying a novel functional domain within the p115 tethering factor required for Golgi ribbon assembly and membrane trafficking
Autor/es:
GRABSKI R; BALKLAVA, Z; WYROZUMSKA, P; SZUL,T; BRANDON, E; ALVAREZ, C; HOLLOWAY, Z; SZTUL, E
Revista:
JOURNAL OF CELL SCIENCE
Editorial:
COMPANY OF BIOLOGISTS LTD
Referencias:
Lugar: Cambridge CB4 0DL; Año: 2012 vol. 125 p. 1896 - 1909
ISSN:
0021-9533
Resumen:
The tethering factor p115 has been shown to facilitate Golgi biogenesis and membrane traffic in cells in culture. However, the role of p115 within an intact animal is largely unknown. Here, we document that RNAi-mediated depletion of p115 in the nematode C. elegans causes accumulation of the yolk protein (YP170) in body cavity and the retention of the yolk receptor RME-2 in the ER and the Golgi within oocytes. Structure-function analyses of p115 have identified two homology (H1-2) regions within the N-terminal globular head and the coiled-coil 1 (CC1) domain as essential for p115 function. We identify a novel C-terminal domain of p115 as necessary for Golgi ribbon formation and cargo trafficking. We show that p115 mutants lacking the fourth CC domain (CC4) act in a dominant negative manner to disrupt Golgi and prevent cargo trafficking in cells containing endogenous p115. Furthermore, using RNAi-mediated "replacement" strategy we show that CC4 is necessary to support Golgi ribbon formation and membrane trafficking in cells depleted of endogenous p115. Biochemical analyses have shown that p115 binds a subset of ER-Golgi SNAREs through CC1 and CC4 domains (Shorter et al., 2002). We show that p115 mutant lacking CC4 binds the SNARE syntaxin-5 and is likely to compete with endogenous p115 for interactions in cells. Our findings show that CC4 is required for p115 function and suggest that both the CC1 and the CC4 SNARE-binding motifs may participate in p115-mediated membrane tethering