Sorting Nexin 11 Regulates Lysosomal Degradation of Plasma Membrane TRPV3

• Published in: Traffic (Copenhagen, Denmark) Denmark), 2016-05, Vol.17 (5), p.500-514
• Main Authors: Li, Caiyue, Ma, Wenbo, Yin, Shikui, Liang, Xin, Shu, Xiaodong, Pei, Duanqing, Egan, Terrance M., Huang, Jufang, Pan, Aihua, Li, Zhiyuan
• Format: Article
• Language: English
• Subjects: degradation; endosomes; HaCaT cells; HEK293 Cells; HeLa Cells; Humans; lysosomes; Lysosomes - metabolism; Plasma; Proteins; Proteolysis; sorting nexin 11; Sorting Nexins - physiology; trafficking; TRPV Cation Channels - metabolism; TRPV3
• ISSN: 1398-9219; 1600-0854
• DOI: 10.1111/tra.12379

The trafficking of ion channels to/from the plasma membrane is essential for the functionality of cells. We report the novel finding that the vesicular trafficking protein SNX11 promotes the trafficking of exogenous TRPV3 ion channel from the plasma membrane to lysosome for degradation via protein–protein interactions in HEK293T cells, and it also decreases the level of endogenous TRPV3 protein in human skin keratinocytes HaCaT cells, which leads to a change in the density of TRPV3 channels on the cell surface. The trafficking of ion channels to/from the plasma membrane is considered an important mechanism for cellular activity and an interesting approach for disease therapies. The transient receptor potential vanilloid 3 (TRPV3) ion channel is widely expressed in skin keratinocytes, and its trafficking mechanism to/from the plasma membrane is unknown. Here, we report that the vesicular trafficking protein sorting nexin 11 (SNX11) downregulates the level of the TRPV3 plasma membrane protein. Overexpression of SNX11 causes a decrease in the level of TRPV3 current and TRPV3 plasma membrane protein in TRPV3‐transfected HEK293T cells. Subcellular localizations and western blots indicate that SNX11 interacts with TRPV3 and targets it to lysosomes for degradation, which is blocked by the lysosomal inhibitors chloroquine and leupeptin. Both TRPV3 and SNX11 are highly expressed in HaCaT cells. We show that TRPV3 agonists‐activated Ca2+ influxes and the level of native TRPV3 total protein in HaCaT cells are decreased by overexpression of SNX11 and increased by knockdown of SNX11. Our findings reveal that SNX11 promotes the trafficking of TRPV3 from the plasma membrane to lysosomes for degradation via protein‐protein interactions, which demonstrates a previously unknown function of SNX11 as a regulator of TRPV3 trafficking from the plasma membrane to lysosomes.