SH3KBP1 - SH3 domain-containing kinase-binding protein 1| Elisa - Clia - Antibody - Protein

Background:

SH3 domain-containing kinase-binding protein 1 (SH3KBP1), also known as CIN85 (Cbl-interacting protein of 85 kDa), is a multifunctional adaptor protein that plays a crucial role in various cellular processes. SH3KBP1 is involved in the regulation of signal transduction pathways, particularly those associated with receptor tyrosine kinases (RTKs) and the immune response. It is implicated in endocytosis, cell migration, and the regulation of apoptosis. The protein is widely expressed in various tissues and has been linked to oncogenic processes, making it a significant subject of study in cancer research.

Protein Structure

SH3KBP1 is composed of several functional domains that facilitate its interaction with other proteins. The primary structure includes three SH3 (Src Homology 3) domains at the N-terminal region, which are crucial for protein-protein interactions. These SH3 domains recognize and bind to proline-rich motifs in target proteins, mediating the formation of multiprotein complexes. The central region of SH3KBP1 contains a proline-rich region, which can serve as a binding site for other SH3 domain-containing proteins. At the C-terminal end, there is a coiled-coil domain that facilitates homo- and hetero-dimerization, important for its function in cellular signaling pathways.

Classification and Subtypes

SH3KBP1 belongs to the family of adaptor proteins characterized by the presence of SH3 domains. While SH3KBP1 itself does not have subtypes, it is part of a broader family of SH3 domain-containing proteins, which includes various members involved in different cellular processes. These proteins are generally classified based on their domain structures and interaction partners.

Function and Biological Significance

SH3KBP1 is involved in multiple cellular functions:

1. Endocytosis: It plays a critical role in the internalization and degradation of RTKs. By interacting with Cbl, an E3 ubiquitin ligase, SH3KBP1 facilitates the ubiquitination and subsequent lysosomal degradation of activated RTKs, thus regulating signal transduction and receptor downregulation.
2. Cell Migration: SH3KBP1 is involved in the reorganization of the actin cytoskeleton, a process essential for cell movement. It interacts with various proteins that modulate actin dynamics, thereby influencing cell migration and invasion, processes that are crucial in cancer metastasis.
3. Apoptosis: SH3KBP1 is implicated in the regulation of apoptosis through its interactions with pro-apoptotic and anti-apoptotic proteins. By modulating apoptotic signaling pathways, it can influence cell survival and death.

Clinical Issues

Alterations in the expression and function of SH3KBP1 have been linked to various diseases, particularly cancer. Overexpression or mutations in SH3KBP1 have been observed in several cancer types, including breast cancer, lung cancer, and gliomas. These alterations can lead to aberrant signal transduction, increased cell proliferation, and enhanced metastatic potential. As a result, SH3KBP1 is considered a potential therapeutic target, and efforts are being made to develop inhibitors that can modulate its activity in cancer therapy.

Summary

SH3KBP1 (CIN85) is a multifunctional adaptor protein essential for regulating endocytosis, cell migration, and apoptosis. Its structure includes three SH3 domains, a proline-rich region, and a coiled-coil domain, enabling interactions with various proteins and forming multiprotein complexes. SH3KBP1's involvement in receptor tyrosine kinase signaling pathways underscores its significance in cellular homeostasis and oncogenesis. Dysregulation of SH3KBP1 is associated with cancer progression, making it a critical target for therapeutic intervention. Understanding the molecular mechanisms of SH3KBP1 can provide insights into its role in health and disease, paving the way for novel cancer treatments.