An assay for clogging the ciliary pore complex distinguishes mechanisms of cytosolic and membrane protein entry

Copyright © 2014 Elsevier Ltd. All rights reserved..

As a cellular organelle, the cilium contains a unique protein composition. Entry of both membrane and cytosolic components is tightly regulated by gating mechanisms at the cilium base; however, the mechanistic details of ciliary gating are largely unknown. We previously proposed that entry of cytosolic components is regulated by mechanisms similar to those of nuclear transport and is dependent on nucleoporins (NUPs), which comprise a ciliary pore complex (CPC). To investigate ciliary gating mechanisms, we developed a system to clog the pore by inhibiting NUP function via forced dimerization. We targeted NUP62, a component of the central channel of the nuclear pore complex (NPC), for forced dimerization by tagging it with the homodimerizing Fv domain. As proof of principle, we show that forced dimerization of NUP62-Fv attenuated (1) active transport of BSA into the nuclear compartment and (2) the kinesin-2 motor KIF17 into the ciliary compartment. Using the pore-clogging technique, we find that forced dimerization of NUP62 attenuated the gated entry of cytosolic proteins but did not affect entry of membrane proteins or diffusional entry of small cytosolic proteins. We propose a model in which active transport of cytosolic proteins into both nuclear and ciliary compartments requires functional NUPs of the central pore, whereas lateral entry of membrane proteins utilizes a different mechanism that is likely specific to each organelle's limiting membrane.

Medienart:

E-Artikel

Erscheinungsjahr:

2014

Erschienen:

2014

Enthalten in:

Zur Gesamtaufnahme - volume:24

Enthalten in:

Current biology : CB - 24(2014), 19 vom: 06. Okt., Seite 2288-94

Sprache:

Englisch

Beteiligte Personen:

Takao, Daisuke [VerfasserIn]
Dishinger, John F [VerfasserIn]
Kee, H Lynn [VerfasserIn]
Pinskey, Justine M [VerfasserIn]
Allen, Ben L [VerfasserIn]
Verhey, Kristen J [VerfasserIn]

Links:

Volltext

Themen:

Journal Article
Nuclear Pore Complex Proteins
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't

Anmerkungen:

Date Completed 11.06.2015

Date Revised 21.10.2021

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.cub.2014.08.012

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM242302203