Molecular Biology of the WWOX Gene That Spans Chromosomal Fragile Site FRA16D

It is now more than 20 years since the FRA16D common chromosomal fragile site was characterised and the WWOX gene spanning this site was identified. In this time, much information has been discovered about its contribution to disease; however, the normal biological role of WWOX is not yet clear. Experiments leading to the identification of the WWOX gene are recounted, revealing enigmatic relationships between the fragile site, its gene and the encoded protein. We also highlight research mainly using the genetically tractable model organism Drosophila melanogaster that has shed light on the integral role of WWOX in metabolism. In addition to this role, there are some particularly outstanding questions that remain regarding WWOX, its gene and its chromosomal location. This review, therefore, also aims to highlight two unanswered questions. Firstly, what is the biological relationship between the WWOX gene and the FRA16D common chromosomal fragile site that is located within one of its very large introns? Secondly, what is the actual substrate and product of the WWOX enzyme activity? It is likely that understanding the normal role of WWOX and its relationship to chromosomal fragility are necessary in order to understand how the perturbation of these normal roles results in disease.

Automated summary

The review discusses the identification of the WWOX gene and its contribution to disease, while highlighting the unclear normal biological role of WWOX. Using the genetically tractable model organism Drosophila melanogaster has shed light on the integral role of WWOX in metabolism and raises outstanding questions about the biological relationship between WWOX and the FRA16D common chromosomal fragile site, as well as the substrate and product of the WWOX enzyme activity. Understanding the normal role of WWOX and its relationship to chromosomal fragility may be crucial in understanding how perturbation of these roles results in disease.