Serine beta-lactamase-like protein LACTB, mitochondrial (Lactb)

Mitochondrial serine protease that functions as a regulator of mitochondrial lipid metabolism (By similarity). Acts by decreasing protein amounts of PISD, a mitochondrial enzyme that converts phosphatidylserine (PtdSer) to phosphatidylethanolamine (PtdEtn), thereby affecting mitochondrial lipid metabolism (By similarity).

It's unclear whether it functions directly by mediating proteolysis of PISD or by mediating proteolysis of another lipid metabolism protein (By similarity). Acts as a tumor suppressor that has the capacity to inhibit proliferation of multiple types of cancer cells: probably by promoting diminished levels of PISD, thereby affecting mitochondrial lipid metabolism (PubMed:28329758).