C11ORF24 Is a Novel Type I Membrane Protein That Cycles between the Golgi Apparatus and the Plasma Membrane in Rab6-Positive Vesicles
PLoS ONE. 2013-12-02; 8(12): e82223
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1. PLoS One. 2013 Dec 2;8(12):e82223. doi: 10.1371/journal.pone.0082223. eCollection
C11ORF24 is a novel type I membrane protein that cycles between the Golgi
apparatus and the plasma membrane in Rab6-positive vesicles.
Fraisier V(1), Kasri A, Miserey-Lenkei S, Sibarita JB, Nair D, Mayeux A, Bardin
S, Toyoda Y, Poser I, Poznyakovskiy A, Goud B, Hyman AA, Dimitrov A.
(1)UMR144, Institut Curie/ CNRS, Cell and Tissue Imaging Platform, Paris, France.
The Golgi apparatus is an intracellular compartment necessary for
post-translational modification, sorting and transport of proteins. It plays a
key role in mitotic entry through the Golgi mitotic checkpoint. In order to
identify new proteins involved in the Golgi mitotic checkpoint, we combine the
results of a knockdown screen for mitotic phenotypes and a localization screen.
Using this approach, we identify a new Golgi protein C11ORF24 (NP_071733.1). We
show that C11ORF24 has a signal peptide at the N-terminus and a transmembrane
domain in the C-terminal region. C11ORF24 is localized on the Golgi apparatus and
on the trans-Golgi network. A large part of the protein is present in the lumen
of the Golgi apparatus whereas only a short tail extends into the cytosol. This
cytosolic tail is well conserved in evolution. By FRAP experiments we show that
the dynamics of C11ORF24 in the Golgi membrane are coherent with the presence of
a transmembrane domain in the protein. C11ORF24 is not only present on the Golgi
apparatus but also cycles to the plasma membrane via endosomes in a pH sensitive
manner. Moreover, via video-microscopy studies we show that C11ORF24 is found on
transport intermediates and is colocalized with the small GTPase RAB6, a GTPase
involved in anterograde transport from the Golgi to the plasma membrane. Knocking
down C11ORF24 does not lead to a mitotic phenotype or an intracellular transport
defect in our hands. All together, these data suggest that C11ORF24 is present on
the Golgi apparatus, transported to the plasma membrane and cycles back through
the endosomes by way of RAB6 positive carriers.
PMID: 24312644 [Indexed for MEDLINE]