CEP55

CEP55 (Centrosomal protein of 55 kDa) is a protein that in humans is encoded by the CEP55 gene. This protein plays a crucial role in cell division, specifically during the final stages of cytokinesis, which is the process by which a single cell divides into two daughter cells. CEP55 is located at the midbody of dividing cells and is essential for the completion of cytokinesis.

Function

CEP55 is a centrosomal protein that is involved in the successful completion of cytokinesis. During the late stages of cell division, CEP55 localizes to the midbody, a structure formed between dividing cells, where it recruits other proteins essential for the abscission phase of cytokinesis. This phase is the final step in cell division, where the bridge between the daughter cells is severed, leading to their physical separation. The recruitment of proteins such as TSG101 and ALIX by CEP55 is critical for the formation of the midbody and the completion of cell division.

Gene

The CEP55 gene is located on human chromosome 10q23.33 and consists of multiple exons. The gene encodes a protein of 55 kDa, which is expressed in various tissues but shows a higher expression level in proliferating cells, reflecting its role in cell division.

Clinical Significance

Alterations in the expression of CEP55 have been associated with various types of cancer. Overexpression of CEP55 has been observed in cancers such as breast cancer, colorectal cancer, and glioblastoma. This overexpression is thought to contribute to tumorigenesis by promoting excessive cell division and preventing the normal mechanisms of cell cycle control. As such, CEP55 is being studied as a potential target for cancer therapy, with the aim of developing treatments that can inhibit its function and thus slow down the proliferation of cancer cells.

Interactions

CEP55 interacts with several proteins that are important for the completion of cytokinesis. These include: - TSG101, which is part of the ESCRT-I complex involved in the final abscission step of cytokinesis. - ALIX, which is involved in membrane repair and cytokinesis. - CDK1 and PLK1, which are kinases that regulate the cell cycle and are necessary for the initiation of cytokinesis.

These interactions are crucial for the recruitment of the necessary components to the midbody and for the regulation of the abscission process.

See Also

- Cell division - Cytokinesis - Centrosome - Cancer