Low-voltage-activated Cav3 calcium channels (T-type) play an essential role in the functioning of the nervous system where they support oscillatory activities that relie on several channel molecular determinants that shape their unique gating properties. In a previous study, we documented the important role of the carboxy proximal region in the functioning of Cav3.3 channels. Here, we explore the ability of a TAT-based cell penetrating peptide containing this carboxy proximal region (TAT-C3P) to modulate the activity of Cav3 channels. We show that chronic application of TAT-C3P on tsA-201 cells expressing Cav3 channels selectively inhibits Cav3.3 channels without affecting Cav3.1 and Cav3.2 channels. Therefore, the TAT-C3P peptide described in this study represents a new tool to address the specific physiological role of Cav3.3 channels, and to potentially enhance our understanding of Cav3.3 in disease.

Institute of Biology and Medical Genetics 1st faculty of Medicine Charles University Prague Czech Republic

Institute of Organic Chemistry and Biochemistry Czech Academy of Sciences Prague Czech Republic

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