Induction of Ran GTP drives ciliogenesis.
Mol Biol Cell
; 22(23): 4539-48, 2011 Dec.
Article
in En
| MEDLINE
| ID: mdl-21998203
ABSTRACT
The small GTPase Ran and the importin proteins regulate nucleocytoplasmic transport. New evidence suggests that Ran GTP and the importins are also involved in conveying proteins into cilia. In this study, we find that Ran GTP accumulation at the basal bodies is coordinated with the initiation of ciliogenesis. The Ran-binding protein 1 (RanBP1), which indirectly accelerates Ran GTP â Ran GDP hydrolysis and promotes the dissociation of the Ran/importin complex, also localizes to basal bodies and cilia. To confirm the crucial link between Ran GTP and ciliogenesis, we manipulated the levels of RanBP1 and determined the effects on Ran GTP and primary cilia formation. We discovered that RanBP1 knockdown results in an increased concentration of Ran GTP at basal bodies, leading to ciliogenesis. In contrast, overexpression of RanBP1 antagonizes primary cilia formation. Furthermore, we demonstrate that RanBP1 knockdown disrupts the proper localization of KIF17, a kinesin-2 motor, at the distal tips of primary cilia in Madin-Darby canine kidney cells. Our studies illuminate a new function for Ran GTP in stimulating cilia formation and reinforce the notion that Ran GTP and the importins play key roles in ciliogenesis and ciliary protein transport.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Nuclear Proteins
/
Cilia
/
Ran GTP-Binding Protein
/
Epithelial Cells
Limits:
Animals
/
Humans
Language:
En
Journal:
Mol Biol Cell
Journal subject:
BIOLOGIA MOLECULAR
Year:
2011
Document type:
Article
Affiliation country:
United States