Pex35 is a regulator of peroxisome abundance

Peroxisomes are cellular organelles with vital functions in lipid, amino acid, and redox metabolism. The cellular formation and dynamics of peroxisomes are governed by PEX genes, however, the regulation of peroxisome abundance is yet poorly understood. Here we use a high-content microscopy screen to identify novel regulators of peroxisome size and abundance. Our screen led to the identification of a previously uncharacterized gene, which we term PEX35, which affects peroxisome abundance. PEX35 encodes a peroxisomal membrane protein, a remote homolog to several curvature generating human proteins. We systematically characterized the genetic and physical interactome as well as the metabolome of mutants in PEX35, and we found that Pex35 functionally interacts with the vesicle budding inducer Arf1 Our results highlight the functional interaction between peroxisomes and the secretory pathway.