Аннотация:Transient receptor potential (TRP) channels constitute a large and functionally versatile ion channel superfamily. TRP channels play an important role in a variety of processes, such as: photoreception, osmoregulation, taste transduction, nociception, temperature sensing, calcium and magnesium re-absorption as well as some motile functions. Most TRP channels studies are focused on the determination of biophysical characteristics, and signaling events which control the channel activity on the plasma membrane whereas, the regulation of spatial dynamics of TRP ion channels remain poorly understood. Evidence, accumulated in recent years, points out the important role of vesicular transport in regulation of TRP channels activity. Two channels TRPV5 and TRPV6 are unique, Ca2+ selective members of the TRP family. Both channels are constitutively active, and play an important role in Ca2+ uptake from apical cell surfaces in the kidney (TRPV5) and in the small intestine (TRPV6). In our previous studies using real-time PCR, immune-blotting and patch-clamp methods we have discovered functionally active TRPV5/V6 channels in the plasma membrane of Jurkat T cells. In this research we explored the mechanisms of regulation TRPV5/V6 channels in Jurkat T cells. In our single-channels recording on Jurkat T cells we discovered that TRPV5/V6 channels were active in absence of any exogenous ligand, mechanical stress or any other stimulus. We suggested that ion flow through these channels is regulated by varying the amount of active channels on the plasma membrane. In turn, the amount of these channels in T cells might be under control of vesicular recycling mechanisms. To test this hypothesis we have studied the impact of the vesicular transport on the overall activity of TRPV5/V6 channels in Jurkat cells. The immunofluorescent protein labeling with specific antibodies revealed the submembrane and cytoplasmic localization of TRPV5 and TRPV6 in Jurkat T cells. Potent dynamin inhibitor dynasore, within several minutes, reduced TRPV5/V6 currents in Jurkat cells in all patch-clamp experiments (n=7). Using Ca2+-sensitive fluorescent dye Fura-2, we discovered that dynasore inhibits the calcium influx in Jurkat cells in all our experiments (n=5). Our results are consistent with data previously obtained by other researchers, which demonstrated the dependence of TRPV5/V6 surface expression on clathrin/dynamin dependent endocytosis and suggest that endo/exocytosis plays an important role in the control of the overall activity of the TRPV5/V6 and therefore can contribute significantly to the calcium entry into T c