PBK (gene)

PBK, also known as TOPK (for Topoisomerase II-interacting protein kinase), is a human gene encoding a serine/threonine kinase protein. It plays a role in cell proliferation, survival, and tumorigenesis.

Function:

The PBK protein is involved in cell cycle regulation, particularly during mitosis. It interacts with and phosphorylates proteins involved in chromosome segregation and spindle assembly. PBK is also implicated in DNA damage response and cell survival pathways. Specifically, research suggests its involvement in the activation of the MAPK signaling pathway, contributing to its role in cell proliferation. Furthermore, PBK appears to be critical for proper kinetochore function and chromosome alignment during cell division.

Expression:

PBK expression is generally low in normal tissues, but it is frequently upregulated in various cancers, including breast cancer, lung cancer, hepatocellular carcinoma, and melanoma. Elevated PBK expression is often associated with poor prognosis and increased tumor aggressiveness.

Clinical Significance:

Because of its overexpression in many tumor types and its critical role in cell proliferation and survival, PBK has emerged as a potential therapeutic target for cancer treatment. Research is ongoing to develop PBK inhibitors that could be used to selectively target and kill cancer cells. Targeting PBK may disrupt cell cycle progression and induce apoptosis in cancer cells.

Structure:

The PBK gene encodes a protein with a kinase domain responsible for its enzymatic activity. This domain contains the ATP-binding site and the catalytic residues necessary for phosphorylating target proteins. The protein also contains regulatory regions that control its activity and localization within the cell.