Involved in mitochondrial metabolism by regulating the balance between mitochondrial fusion and fission (PubMed:27863209). May act as a regulator of mitochondrial fission that promotes DNM1L-dependent fission through activation of DNM1L (PubMed:27863209). May be involved in peroxisome organization (By similarity). Up-regulated following cold exposure and upon fasting. Age-dependent pathologies, characterized by accelerated aging in the retina similar to macular degeneration of the retina (PubMed:27863209). Retina show higher sensitivity to oxidative stress (PubMed:27863209). Defects are caused by impaired balance between mitochondrial fusion and fission (PubMed:27863209). Belongs to the TMEM135 family.