Active breakpoint cluster region-related protein (ABR)

Active breakpoint cluster region-related protein (ABR) is a multifunctional regulatory enzyme containing both GTPase-activating protein (GAP) and guanine nucleotide exchange factor (GEF) domains, enabling it to exert opposing control over Rho family GTPases such as Rac1, CDC42, and RHOA. Highly expressed in the brain and widely distributed in other tissues, ABR modulates cytoskeletal dynamics, cell motility, division, growth, and adhesion. It is a critical inhibitor of Rac1, acting as a tumor suppressor in leukemia and playing key roles in immune cell migration, neural development, and maintenance of genomic stability during cell division. Dysfunction or loss of ABR leads to enhanced cell motility, abnormal immune activation, and neurodevelopmental defects. ABR’s regulatory complexity and central role in cell signaling make it a potential yet challenging therapeutic target in oncology, immunology, and neurobiology.

Other names

Active breakpoint cluster region-related proteinABRMDBRhoGEF and GTPase activating proteinActive BCR-related

Potential therapies would target ABR’s: - Modulation of GTPase activity: inhibiting or enhancing its activity to control cell growth or motility, especially through its GAP or GEF domains, affecting Rac1, CDC42, or RHOA signaling. - Tumor suppressor function by enhancing its inhibition of oncogenic Rac1 signaling.