Channel Activity Detector

About

Introduction: Membrane proteins carry out many important physiological functions in all cells responding to signaling and regulation. Oocyte injection has been widely used for monitoring membrane ion channel activity for years (voltage clamp, patch clamp, etc.) and is well-known for studying channels in a controlled in vivo cellular environment. This method is critical in analyzing domain mutations, and drug and drug resistance screening. However, not all target protein channels can be expressed in the oocytes, and there is no methodology available for the stud of complex systems. Therefore, there remains a need for additional methods of analyzing the characteristics and regulation of membrane proteins, such as channels, pumps, and receptors. Technology: Georgia State University researchers developed a simple and efficient method to monitor channel activity by direct injection of proteoliposomes instead of cDNA. The proteo-liposome comprises an ion channel-forming recombinant protein. Data demonstrate that pre-assembled membrane proteins embedded in liposomes are able to incorporate into oocyte plasma membranes upon injection, which enables the detection of channel activity. Generally, the expression usually takes 2-3 days with cDNA injection with 20-30% expression rates. However, the proteoliposome injection significantly increases the expression time to about 30 minutes to three hours.