Sun S, Liu S, Zhang Z, Zeng W, Sun C, Tao T, Lin X, Feng XH

Ubiquitin-like domain-containing C-terminal domain phosphatase 1 (UBLCP1), an FCP/SCP phosphatase family member, was identified as the first proteasome phosphatase. UBLCP1 binds to proteasome subunit Rpn1 and dephosphorylates the proteasomein vitroHowever, it is still unclear which proteasome subunit(s) are thebona fidesubstrate(s) of UBLCP1 and the precise mechanism for proteasome regulation remains ...

Read More

elusive. Here, we show that UBLCP1 selectively binds to the 19S regulatory particle (RP) through its interaction with Rpn1, but not the 20S core particle (CP) or the 26S proteasome holoenzyme. In the RP, UBLCP1 dephosphorylates the subunit Rpt1, impairs its ATPase activity, and consequently disrupts the 26S proteasome assembly, yet it has no effects on the RP assembly from precursor complexes. The Rpn1-binding and phosphatase activities of UBLCP1 are essential for its function on Rpt1 dephosphorylation and proteasome activity bothin vivoandin vitroOur study establishes the essential role of the UBLCP1/Rpn1/Rpt1 complex in regulating proteasome assembly.

Date: May. 01, 2017

View in: Pubmed Google Scholar

207485