ATP-dependent metalloprotease that catalyzes the degradation of folded and unfolded proteins with a suitable degron sequence in the mitochondrial intermembrane region (PubMed:24315374, PubMed:26923599, PubMed:27786171, PubMed:31695197, PubMed:33237841, PubMed:36206740). Plays an important role in regulating mitochondrial morphology and function by cleaving OPA1 at position S2, giving rise to a form of OPA1 that promotes maintenance of normal mitochondrial structure and mitochondrial protein metabolism (PubMed:18076378, PubMed:26923599, PubMed:27495975, PubMed:33237841). Ensures cell proliferation, maintains normal cristae morphology and complex I respiration activity, promotes antiapoptotic activity and protects mitochondria from the accumulation of oxidatively damaged membrane proteins (PubMed:22262461). Required to control the accumulation of nonassembled respiratory chain subunits (NDUFB6, OX4 and ND1) (PubMed:22262461). Involved in the mitochondrial adaptation in response to various signals, such as stress or developmental cues, by mediating degradation of mitochondrial proteins to rewire the mitochondrial proteome (PubMed:31695197). Catalyzes degradation of mitochondrial proteins, such as translocases, lipid transfer proteins and metabolic enzymes in response to nutrient starvation in order to limit mitochondrial biogenesis: mechanistically, YME1L1 is activated by decreased phosphatidylethanolamine levels caused by LPIN1 activity in response to mTORC1 inhibition (PubMed:31695197). Acts as a regulator of adult neural stem cell self-renewal by promoting mitochondrial proteome rewiring, preserving neural stem and progenitor cells self-renewal (By similarity). Required for normal, constitutive degradation of PRELID1 (PubMed:27495975). Catalyzes the degradation of OMA1 in response to membrane depolarization (PubMed:26923599). Mediates degradation of TIMM17A downstream of the integrated stress response (ISR) (PubMed:24315374). Catalyzes degradation of MICU1 when MICU1 is not assembled via an interchain disulfide (PubMed:36206740). Cleaves STARD7 mitochondrial targeting sequence (PubMed:29301859). {ECO:0000250|UniProtKB:O88967, ECO:0000269|PubMed:18076378, ECO:0000269|PubMed:22262461, ECO:0000269|PubMed:24315374, ECO:0000269|PubMed:26923599, ECO:0000269|PubMed:27495975, ECO:0000269|PubMed:27786171, ECO:0000269|PubMed:29301859, ECO:0000269|PubMed:31695197, ECO:0000269|PubMed:33237841, ECO:0000269|PubMed:36206740}. This is the function of Ensembl gene identifier ENSG00000136758 (YME1L1, YME1 like 1 ATPase).