DOCK2

DOCK2 (Dedicator of Cytokinesis 2) is a hematopoietic cell-enriched atypical guanine nucleotide exchange factor that primarily activates the small GTPases RAC1 and RAC2, thereby regulating actin cytoskeleton remodeling and immune cell behavior^[1][2]. Mechanistically, DOCK2 controls lymphocyte trafficking, homing, adhesion, polarity, and migration through RAC-dependent cytoskeletal reorganization, making it a central regulator of leukocyte motility and immune surveillance^[1][2][3]. DOCK2 also contributes to T-cell activation and immune synapse function by supporting actin dynamics required for effective signaling between lymphocytes and antigen-presenting cells^[2]. In disease settings, genetic deficiency of DOCK2 is associated with severe combined immunodeficiency characterized by impaired T-cell, B-cell, and natural killer cell function, highlighting its essential role in host defense and immune homeostasis^[3]. Beyond immunodeficiency, altered DOCK2 activity has been linked to immune-related disorders and inflammatory pathologies through its effects on immune-cell activation, cytokine regulation, and RAC signaling pathways^[3]. Compared with related DOCK family members, DOCK2 is distinguished by its predominant expression in leukocytes and its specialized role in regulating immune-cell migration and activation, whereas other family members display broader tissue distributions and functions^[4]. For experimental applications, DOCK2 serves as a valuable molecular target for investigating RAC-dependent signaling, leukocyte trafficking, chemotaxis, and immune dysfunction, and studies have demonstrated that DOCK2 dimerization is required for efficient RAC activation and lymphocyte migration in cellular models^[5].