%0 Journal Article
%T A genome-wide screen links peroxisome regulation with Wnt signaling through RNF146 and TNKS/2.
%A Vu JT
%A Tavasoli KU
%A Sheedy CJ
%A Chowdhury SP
%A Mandjikian L
%A Bacal J
%A Morrissey MA
%A Richardson CD
%A Gardner BM
%J J Cell Biol
%V 223
%N 10
%D 2024 Oct 7
%M 38967608
%F 8.077
%R 10.1083/jcb.202312069
%X Peroxisomes are membrane-bound organelles harboring metabolic enzymes. In humans, peroxisomes are required for normal development, yet the genes regulating peroxisome function remain unclear. We performed a genome-wide CRISPRi screen to identify novel factors involved in peroxisomal homeostasis. We found that inhibition of RNF146, an E3 ligase activated by poly(ADP-ribose), reduced the import of proteins into peroxisomes. RNF146-mediated loss of peroxisome import depended on the stabilization and activity of the poly(ADP-ribose) polymerases TNKS and TNKS2, which bind the peroxisomal membrane protein PEX14. We propose that RNF146 and TNKS/2 regulate peroxisome import efficiency by PARsylation of proteins at the peroxisome membrane. Interestingly, we found that the loss of peroxisomes increased TNKS/2 and RNF146-dependent degradation of non-peroxisomal substrates, including the β-catenin destruction complex component AXIN1, which was sufficient to alter the amplitude of β-catenin transcription. Together, these observations not only suggest previously undescribed roles for RNF146 in peroxisomal regulation but also a novel role in bridging peroxisome function with Wnt/β-catenin signaling during development.