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Published on: August 10, 2021
Ubiquitination and dynactin regulate TMEPAI lysosomal trafficking.
Shenheng Luo1, Lei Jing1, Tian Zhao1
1School of Biotechnology, Tianjin University of Science and Technology, Key Lab of Industrial Fermentation Microbiology of the Ministry of Education, Tianjin, 300457, China.
The transmembrane prostate androgen-induced protein (TMEPAI) is transported to lysosomes via a clathrin and CI-M6PR pathway. Ubiquitination and specific protein interactions regulate this crucial TMEPAI trafficking mechanism in tumorigenesis.
Area of Science:
- Cell Biology
- Molecular Biology
- Cancer Research
Background:
- Transmembrane prostate androgen-induced protein (TMEPAI) is elevated in tumors and stabilizes lysosomes.
- The mechanism of TMEPAI lysosomal trafficking is currently unknown.
Purpose of the Study:
- To elucidate the molecular mechanism and pathway governing TMEPAI transport to the lysosome.
Main Methods:
- Investigated TMEPAI trafficking using clathrin and CI-M6PR mediation.
- Analyzed TMEPAI ubiquitination at the C-terminal region.
- Examined interactions with Hrs, STAM, and dynactin subunits.
- Utilized domain deletion analysis (aa 132-155) to assess binding and trafficking.
Main Results:
- Clathrin and CI-M6PR mediate TMEPAI transport from the Golgi to the endo-lysosomal pathway.
- TMEPAI ubiquitination serves as a signal for lysosomal trafficking.
- Hrs and STAM binding are essential for TMEPAI lysosomal transport.
- The aa 132-155 domain is critical for TMEPAI binding and proper trafficking; its deletion causes mis-trafficking to the plasma membrane.
Conclusions:
- Identified a novel pathway and mechanism for TMEPAI lysosomal transport.
- TMEPAI trafficking is regulated by ubiquitination and specific protein interactions.
- Understanding TMEPAI transport is key to its role in tumorigenesis.
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