Ras-related C3 botulinum toxin substrate 3 (Rac3) is a G protein that in humans is encoded by the RAC3gene.[5] It is an important component of intracellularsignalling pathways. Rac3 is a member of the Rac subfamily of the Rho family of small G proteins.[6][7] Members of this superfamily appear to regulate a diverse array of cellular events, including the control of cell growth, cytoskeletal reorganization, and the activation of protein kinases.[5]
RAC3 gene is located in the third sub-band of the fifth band in the second region of the q arm on chromosome 17. There's many tumor suppressor genes that are located around the RAC3 gene.[12]
Since the RAC3 gene is over-expressed in carcinoma cells, it can function as a therapeutic target for the treatment of different cancer such as lung adenocarcinoma. To become invasive, epithelial cells have to transform into mesenchymal cells and the transformation is regulated by the RAC3 gene. As a result, if the RAC3 gene is silenced, lung adenocarcinoma cells cannot metastasize. In addition, drugs designed to silence the RAC3 gene lead to the apoptosis of tumor cells, thus preventing the cells from colonizing.[13]
Mutations of the RAC3 gene may result in neurodevelopmental disorder with structural brain anomalies and dysmorphic facies, first described in 2018 by White et al.
^Courjal F, Chuchana P, Theillet C, Fort P (September 1997). "Structure and chromosomal assignment to 22q12 and 17qter of the ras-related Rac2 and Rac3 human genes". Genomics. 44 (2): 242–6. doi:10.1006/geno.1997.4871. PMID9299243.
^Morris CM, Haataja L, McDonald M, Gough S, Markie D, Groffen J, Heisterkamp N (2000). "The small GTPase RAC3 gene is located within chromosome band 17q25.3 outside and telomeric of a region commonly deleted in breast and ovarian tumours". Cytogenetics and Cell Genetics. 89 (1–2): 18–23. doi:10.1159/000015583. PMID10894930. S2CID22901214.
Courjal F, Chuchana P, Theillet C, Fort P (September 1997). "Structure and chromosomal assignment to 22q12 and 17qter of the ras-related Rac2 and Rac3 human genes". Genomics. 44 (2): 242–6. doi:10.1006/geno.1997.4871. PMID9299243.
Morris CM, Haataja L, McDonald M, Gough S, Markie D, Groffen J, Heisterkamp N (2000). "The small GTPase RAC3 gene is located within chromosome band 17q25.3 outside and telomeric of a region commonly deleted in breast and ovarian tumours". Cytogenetics and Cell Genetics. 89 (1–2): 18–23. doi:10.1159/000015583. PMID10894930. S2CID22901214.
De Langhe S, Haataja L, Senadheera D, Groffen J, Heisterkamp N (May 2002). "Interaction of the small GTPase Rac3 with NRBP, a protein with a kinase-homology domain". International Journal of Molecular Medicine. 9 (5): 451–9. doi:10.3892/ijmm.9.5.451. PMID11956649.
Hwang SL, Chang JH, Cheng TS, Sy WD, Lieu AS, Lin CL, et al. (June 2005). "Expression of Rac3 in human brain tumors". Journal of Clinical Neuroscience. 12 (5): 571–4. doi:10.1016/j.jocn.2004.08.013. PMID15993075. S2CID24196818.