IRSp53

IRSp53, also known as Insulin Receptor Substrate p53, is a protein encoded by the IRS53 gene. It is a scaffolding protein that plays a role in various cellular signaling pathways, particularly those related to cell growth, survival, and migration. IRSp53 is a key mediator of signals initiated by receptor tyrosine kinases, such as the insulin receptor and the epidermal growth factor receptor. Upon activation of these receptors, IRSp53 becomes tyrosine phosphorylated and interacts with a multitude of downstream signaling molecules. This interaction facilitates the recruitment of these molecules to the plasma membrane, thereby enabling their activation and subsequent signal transduction.

The protein contains several domains that are crucial for its function, including an SH3 domain, a PDZ domain, and a pleckstrin homology (PH) domain. These domains allow IRSp53 to bind to a diverse range of proteins, including cytoskeletal components, guanine nucleotide exchange factors, and other signaling enzymes. Through these interactions, IRSp53 contributes to the regulation of actin cytoskeleton dynamics, which is essential for processes like cell motility and invasion. Aberrant expression or function of IRSp53 has been implicated in the development and progression of several types of cancer, where it can promote tumor cell proliferation and metastasis. Research into IRSp53 continues to explore its multifaceted roles in normal physiology and disease pathogenesis.