Diffusion of a soluble protein through a sensory cilium

Feb 22, 2010
Calvert et al. measured protein diffusion through a sensory cilium. Credit: Calvert, P.D. 2010. J. Gen. Physiol. doi:10.1085/jgp.200910322.

A team of researchers led by Peter Calvert (SUNY Upstate Medical University) has, for the first time, measured the diffusion coefficient of a protein in a primary cilium and in other major compartments of a highly polarized cell. The study appears in the March issue of the Journal of General Physiology.

Transport of proteins to and from cilia is crucial for normal cell function and survival, and interruption of transport has been implicated in degenerative diseases and neoplastic diseases, such as cancer. Researchers believe that cilia impose selective barriers to the movement of proteins, but because of the narrow and complex structure of cilia—with diameters near or below the resolution of light microscopy—this hypothesis has been difficult to examine.

Using confocal and multiphoton microscopy, Calvert and his team—including William Schiesser (Lehigh University) and Edward Pugh (University of California, Davis)—measured the mobility of PAGFP (photoactivatable ) in the connecting cilium (CC) of retinal rod photoreceptors in frogs, as well as in the subcellular compartments bridged by the CC. In addition, the team measured the overall time for the protein concentration to equilibrate within and between compartments.

The results establish that the CC does not pose a major barrier to protein diffusion within the rod cell, but that the axial diffusion in each of the rod's compartments is substantially delayed relative to that in .

Explore further: New compounds protect nervous system from the structural damage of MS

More information: Calvert, P.D. 2010. J. Gen. Physiol. doi:10.1085/jgp.200910322

add to favorites email to friend print save as pdf

Related Stories

Scientists study cilia -- microscopic hair

May 05, 2006

Texas scientists studying microscopic hairs called cilia say they found an internal structure that's responsible for a cell's response to external signals.

Some skin cancer may be mediated by primary cilia activity

Aug 23, 2009

Tiny, solitary spikes that stick out of nearly every cell in the body play a central role in a type of skin cancer, new research has found. The discovery in mice shows that the microscopic structures known as primary cilia ...

Recommended for you

Mystery of the reverse-wired eyeball solved

Feb 27, 2015

From a practical standpoint, the wiring of the human eye - a product of our evolutionary baggage - doesn't make a lot of sense. In vertebrates, photoreceptors are located behind the neurons in the back of the eye - resulting ...

Neurons controlling appetite made from skin cells

Feb 27, 2015

Researchers have for the first time successfully converted adult human skin cells into neurons of the type that regulate appetite, providing a patient-specific model for studying the neurophysiology of weight ...

Quality control for adult stem cell treatment

Feb 27, 2015

A team of European researchers has devised a strategy to ensure that adult epidermal stem cells are safe before they are used as treatments for patients. The approach involves a clonal strategy where stem cells are collected ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.