Protein Wnt-3a is a protein that in humans is encoded by the WNT3Agene.[5]
The WNT gene family consists of structurally related genes that encode secreted signaling proteins. These proteins have are critical in tissue homeostasis, embryonic development, and disease.
Signaling and Related Genes
WNT3A is highly related to the WNT3 gene in sequence and protein function. WNT3A and WNT3 signal similarly through primarily the beta-catenin/Tcf pathway. WNT3A is located in the genome beside the WNT9A gene across many vertebrates. Similarly, the WNT3 gene occurs in the genome beside the WNT9B gene. WNT9A and WNT9B signal through the beta-catenin/Tcf pathway but do not play related roles as WNT3A and WNT3 in the same cellular processes.
Role in Disease
WNT3A is not linked to particular genetic disorder in humans. Mice that have a genetic mutation in the WNT3A die during early embryogenesis and fail to correctly form axial tissues.[6] Rodent Wnt3a promotes the beta-catenin/Tcf pathway which is tumor inducing and can cause cancer when expressed in particular cell populations.[7]
Role in embryonic development
Embryonic development is the process where the body plan is created. From studies in vertebrate model systems we can infer the roles of particular genes in human anatomical structures. Wnt3a plays a role in these processes:
Wnt3A patterns a multipotent stem cell population that form neurons, muscles, bones, and cartilage of the torso region. Wnt3a instructs these multipotent stems cells to form muscle, bone, and cartilage progenitors over forming neurons.[8] Wnt3A also regulates the Notch pathway to control the segmentation clock needed for normal torso development [9][10]
Left-Right patterning
Wnt3a is in a signaling pathway that activates the gene Nodal which is left side signaling determinant [11]
Intestine - Colon
The colon portion of the gastrointestinal tract is completely dependent on Wnt3a and Wnt3a selectively causes the growth of colon progenitors [12]
Wnt3a promotes hematopoietic stem cell self-renewal. Wnt3a is needed for myeloid but not B-lymphoid development at the progenitor level, and affected immature thymocyte differentiation [14]
Brain - Hippocampus
Wnt3a is needed for formation of the hippocampus portion of the brain [15]
Huguet EL, McMahon JA, McMahon AP, Bicknell R, Harris AL (May 1994). "Differential expression of human Wnt genes 2, 3, 4, and 7B in human breast cell lines and normal and disease states of human breast tissue". Cancer Research. 54 (10): 2615–21. PMID8168088.
Tanaka K, Okabayashi K, Asashima M, Perrimon N, Kadowaki T (July 2000). "The evolutionarily conserved porcupine gene family is involved in the processing of the Wnt family". European Journal of Biochemistry. 267 (13): 4300–11. doi:10.1046/j.1432-1033.2000.01478.x. PMID10866835.
Katoh M (February 2002). "Regulation of WNT3 and WNT3A mRNAs in human cancer cell lines NT2, MCF-7, and MKN45". International Journal of Oncology. 20 (2): 373–7. doi:10.3892/ijo.20.2.373. PMID11788904.
Katoh M (March 2002). "Molecular cloning and expression of mouse Wnt14, and structural comparison between mouse Wnt14-Wnt3a gene cluster and human WNT14-WNT3A gene cluster". International Journal of Molecular Medicine. 9 (3): 221–7. doi:10.3892/ijmm.9.3.221. PMID11836627.
