Display Settings:

Format

Send to:

Choose Destination
See comment in PubMed Commons below
J Cell Sci. 2007 Jul 15;120(Pt 14):2413-23.

A cytoskeletal-based perimeter fence selectively corrals a sub-population of cell surface Kv2.1 channels.

Author information

  • 1Department of Biomedical Sciences, Colorado State University, Ft. Collins, CO 80523, USA.

Abstract

The Kv2.1 delayed-rectifier channel trafficks to 1-3 microm(2) clusters on the surface of neurons and transfected HEK cells. Single quantum dot (Qdot) tracking and FRAP approaches were used to quantify the diffusion of GFP-labeled Kv2.1 channels on the cell surface and address the mechanisms underlying the formation of these unique membrane structures. Mean square displacement analysis of single Kv2.1 channel tracks inside or outside the surface clusters yielded mean diffusion coefficients of 0.03+/-0.02 microm(2)/second and 0.06+/-0.05 microm(2)/second, respectively. Kv2.1 channels outside the clusters effectively ignore the cluster boundary, readily diffusing through these microdomains. However, in 5% of the tracks analyzed, single, non-clustered channels were observed to cross into a cluster and become corralled within the cluster perimeter. Alexa Fluor 594-labelled phalloidin staining and mCherry-Kv2.1 co-expression with GFP-actin indicated that the Kv2.1 surface clusters form where the cortical actin cytoskeleton is reduced. Kv2.1 channels lacking the C-terminus do not form clusters, freely diffusing over the cell surface with a mean diffusion coefficient of 0.07+/-0.04 microm(2)/second. These data support a model whereby the Kv2.1 clusters are formed by sub-membrane cytoskeletal structures that limit the lateral diffusion of only the sub-population of Kv2.1 channels carrying the appropriate modifications on the Kv2.1 C-terminus.

PMID:
17606996
[PubMed - indexed for MEDLINE]
Free full text
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Icon for HighWire
    Loading ...
    Write to the Help Desk