Objectives: 

The voltage-dependent K+ channel Kv1.3 participates in many physiological events like proliferation and activation of immunitary cells, membrane repolarization in sensory neurons, vascular smooth muscle tone, insulin resistance and obesity. In most cases, Kv1.3 concentrates in specific membrane microdomains called lipid rafts. These domains act as platforms where signaling pathways converge. Caveolae are a specialized form of lipid rafts with, an omega shaped structure build up by the structural protein caveolin. Evidence indicates that Kv1.3 functionality relays not only on expression but also on localization at the plasma membrane. The importance of this spatial regulation is manifest when an altered Kv1.3 distribution is related with the appearance of disease. Therefore, the mechanisms that govern Kv1.3 function are of considerable interest.

Materials: 

We performed structure-function studies by using a repertoire of Kv1.3 mutants and stable HEK-293 cell lines with or without caveolins, characterized putative interactions and analyzed membrane dynamics by single molecule tracking.

Results: 

In this study we characterized the relationship between Kv1.3 and caveolins. In addition, we analyzed the presence of putative caveolin-binding domains in Kv1.3 that could explain their interaction.

Conclusions: 

As Kv1.3 is considered an important pharmacological target for different autoimmunitary diseases and obesity, it is important to bring light to the Kv1.3 interactions with other partners that can regulate channel surface distribution and function.

Supported by BFU2011-23268 and CSD2008-00005 to AF (MINECO, Spain).