Component of the MICOS complex, a large protein complex of the mitochondrial inner membrane that plays crucial roles in the maintenance of crista junctions, inner membrane architecture, and formation of contact sites to the outer membrane (PubMed:25781180, PubMed:32567732, PubMed:33130824). Plays an important role in the maintenance of the MICOS complex stability and the mitochondrial cristae morphology (PubMed:25781180, PubMed:32567732, PubMed:33130824). Has also been shown to function as a transcription factor which binds to the BAG1 promoter and represses BAG1 transcription (PubMed:22567091).