Related Experiment Video

Updated: Jun 17, 2026

Application of High-speed Super-resolution SPEED Microscopy in Live Primary Cilium
07:53

Application of High-speed Super-resolution SPEED Microscopy in Live Primary Cilium

Published on: January 16, 2018

The cytoplasmic tail of fibrocystin contains a ciliary targeting sequence

John A Follit1, Lixia Li, Yvonne Vucica

  • 1Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA.

The Journal of Cell Biology
|January 6, 2010
PubMed

Insights

Researchers identified a specific sequence in fibrocystin that directs proteins to cilia. This fibrocystin ciliary targeting sequence (CTS) binds Rab8, controlling protein transport to the cilium.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Genetics

Background:

  • Primary cilia are crucial for sensory functions, relying on specific membrane proteins.
  • The mechanisms for targeting these ciliary proteins remain largely unknown.

Purpose of the Study:

  • To investigate the ciliary targeting sequence (CTS) of fibrocystin, the protein linked to autosomal recessive polycystic kidney disease.
  • To elucidate the molecular mechanisms controlling protein trafficking to primary cilia.

Main Methods:

  • Dissection and analysis of the fibrocystin ciliary targeting sequence (CTS).
  • Use of green fluorescent protein (GFP) as a reporter to track protein localization.
  • Coimmunoprecipitation assays to identify binding partners of the CTS, focusing on Rab GTPases.

Main Results:

  • An 18-residue motif in fibrocystin's cytoplasmic tail acts as the CTS.
  • This CTS directs GFP to cilia in ciliated cells and to lipid rafts in non-ciliated cells.
  • Rab8 specifically binds to the CTS, and dominant-negative Rab8 inhibits ciliary trafficking.

Conclusions:

  • The fibrocystin CTS utilizes Rab8 binding to regulate protein transport through the endomembrane system to the cilium.
  • Understanding this trafficking pathway is key to deciphering ciliary protein localization and function.

More Related Videos

In Vitro Analysis of PDZ-dependent CFTR Macromolecular Signaling Complexes10:05

In Vitro Analysis of PDZ-dependent CFTR Macromolecular Signaling Complexes

Published on: August 13, 2012

Förster Resonance Energy Transfer Mapping: A New Methodology to Elucidate Global Structural Features07:09

Förster Resonance Energy Transfer Mapping: A New Methodology to Elucidate Global Structural Features

Published on: March 16, 2022

Related Concept Videos

Tail-anchoring of Proteins in the ER Membrane01:45

Tail-anchoring of Proteins in the ER Membrane

Tail-anchored, or TA, proteins are estimated to make up to 3-5% of membrane proteins found in the eukaryotic cell. Such proteins have a single transmembrane domain located approximately 30 amino acid residues upstream from the C-terminal end. As a result, the signal recognition particle (SRP) cannot guide a TA protein to the ER membrane for cotranslational insertion. Hence, they are integrated into the ER membrane post-translationally using their C-terminal end as the anchor. TA proteins...
Microtubules in Signaling01:22

Microtubules in Signaling

The primary cilium, made up of microtubules, acts as antennae on the cell surfaces for relaying external stimuli into the cells. These fine hair-like structures are present, generally one per cell. These are non-motile cilia in a 9+0 microtubules arrangement, where the central pair of microtubules are absent. The primary cilia arise from the basal body embedded in the cell membrane. Intraflagellar transport (IFT) carries requisite proteins from the cytoplasm to the cilium because the primary...
Mechanism of Ciliary Motion01:05

Mechanism of Ciliary Motion

The ciliary structures were first seen in 1647 by Antonie Leeuwenhoek while observing the protozoans. In lower organisms, these appendages are responsible for cell movement, while in higher organisms, these appendages help in the movement of the extracellular fluids within the body cavities.
The cilia are made up of microtubules in a 9+2 arrangement, with nine microtubule doublet ring bundles, surrounding a pair of central singlet microtubule bundles. The doublet microtubule bundles are...
Mechanism of Ciliary Motion01:05

Mechanism of Ciliary Motion

The ciliary structures were first seen in 1647 by Antonie Leeuwenhoek while observing the protozoans. In lower organisms, these appendages are responsible for cell movement, while in higher organisms, these appendages help in the movement of the extracellular fluids within the body cavities.
The cilia are made up of microtubules in a 9+2 arrangement, with nine microtubule doublet ring bundles, surrounding a pair of central singlet microtubule bundles. The doublet microtubule bundles are...
Microtubules in Cell Motility01:24

Microtubules in Cell Motility

Microtubules are thick hollow cylindrical proteins that help form the cytoskeleton. Microtubules have varied roles in the cell. These filaments help form cellular appendages like cilia and flagella, which are responsible for locomotion. The cilia arise from basal bodies, separated from the main body by a membrane-like structure forming the transition zone. This zone is the gate for the entry of lipids and proteins, creating a unique composition of lipids and proteins in the ciliary membrane and...
Catenins01:23

Catenins

Catenins are characterized by multiple binding domains and dynamic structures that allow them to function as linker proteins in cell junction complexes. All catenins, except α-catenin, contain a characteristic protein sequence called the armadillo repeat and are therefore also called armadillo proteins.
Catenins in Cell Junctions
Catenins bind to cell adhesion molecules such as cadherins and link them to different cytoskeletal proteins depending on the type of cell junction. At the adherens...