Human ALK Tyrosine Kinase Receptor (ALK) Protein

Background

The ALK (anaplastic lymphoma kinase) gene encodes a receptor tyrosine kinase, which is a type of cell surface receptor that plays a role in signaling pathways involved in cell growth, proliferation, and differentiation. The ALK protein belongs to the insulin receptor superfamily and is normally expressed in specific tissues during embryonic development, where it helps regulate normal cell growth and development. While ALK expression is typically limited to certain tissues during development, aberrant activation of the ALK gene can occur in various cancers due to chromosomal rearrangements, gene amplification, or activating mutations. These alterations lead to the overexpression or constitutive activation of the ALK protein, contributing to oncogenesis (the formation of cancer).The most well-known oncogenic alteration involving the ALK gene is the fusion of the ALK gene with another gene, resulting in a chimeric fusion protein with constitutive kinase activity. This fusion protein can drive cellular transformation and tumorigenesis.