Molecular insights into human phosphatidylserine synthase 1 reveal its inhibition promotes LDL uptake.

ABSTRACT: In mammalian cells, two phosphatidylserine (PS) synthases drive PS synthesis. Gain-of-function mutations in the Ptdss1 gene lead to heightened PS production, causing Lenz-Majewski syndrome (LMS). Recently, pharmacological inhibition of PSS1 has been shown to suppress tumorigenesis. Here, we report the cryo-EM structures of wild-type human PSS1 (PSS1^WT), the LMS-causing Pro269Ser mutant (PSS1^P269S), and PSS1^WT in complex with its inhibitor DS55980254. PSS1 contains 10 transmembrane helices (TMs), with TMs 4-8 forming a catalytic core in the luminal leaflet. These structures revealed a working mechanism of PSS1 akin to the postulated mechanisms of the membrane-bound O-acyltransferase family. Additionally, we showed that both PS and DS55980254 can allosterical

SUBMITTER: Long T 

PROVIDER: S-EPMC11455612 | biostudies-literature | 2024 Oct

REPOSITORIES: biostudies-literature