Ccdc51, also known as MITOK, encodes a mitochondrial coiled-coil domain-containing 51 protein. It is crucial for mitochondrial function, playing a role in mitochondrial fission dynamics, and is associated with maintaining normal mitochondrial morphology and organelle homeostasis. It may also be involved in pathways related to endocytic trafficking as it was detected in early endosomes in an EGF-dependent manner [4].

Mutated Ccdc51 has been identified as a candidate gene defect for autosomal recessive rod-cone dystrophy. A homozygous frameshift variant in Ccdc51 was found in a patient, and MITOK ablation causes mitochondrial dysfunction. Ccdc51 localizes in the retina, specifically in the inner segments of photoreceptors, which are rich in mitochondria [1]. Additionally, knockdown of Ccdc51 in human cells leads to reduced rates of mitochondrial fission, and its overexpression promotes association with Drp1 and induces mitochondrial fragmentation, suggesting it is a positive effector of mitochondrial fission. It can also partially rescue yeast Δmdm33 cells, indicating functional analogy with yeast Mdm33, a protein previously implicated in mitochondrial fission-related processes [2,3].

In conclusion, Ccdc51 is essential for mitochondrial function, especially in mitochondrial fission. Its dysfunction is associated with non-syndromic inherited retinal disorders, highlighting its significance in understanding the pathogenesis of such diseases. Studies on Ccdc51, including those using gene-knockdown models, contribute to uncovering the role of mitochondrial proteins in maintaining normal physiological functions and the development of related diseases.