Oral-facial-digital type I protein is required for primary cilia formation and left-right axis specification

The oral-facial-digital type I (OFD1) syndrome (OMIM 311200) is a human developmental disorder; affected individuals have craniofacial and digital abnormalities and, in 15% of cases, polycystic kidney. The disease is inherited as an X-linked dominant male-lethal trait. Using a Cre-loxP system, we generated knockout animals lacking Ofd1 and reproduced the main features of the disease, albeit with increased severity, possibly owing to differences of X inactivation patterns between human and mouse. We found failure of left-right axis specification in mutant male embryos, and ultrastructural analysis showed a lack of cilia in the embryonic node. Formation of cilia was defective in cystic kidneys from heterozygous females, implicating ciliogenesis as a mechanism underlying cyst development. In addition, we found impaired patterning of the neural tube and altered expression of the 5' Hoxa and Hoxd genes in the limb buds of mice lacking Ofd1, suggesting that Ofd1 could have a role beyond primary cilium organization and assembly.     

γ-Glutamyltranspeptidases: sequence, structure, biochemical properties, and biotechnological applications

γ-Glutamyltranspeptidases (γ-GTs) are ubiquitous enzymes that catalyze the hydrolysis of γ-glutamyl bonds in glutathione and glutamine and the transfer of the released γ-glutamyl group to amino acids or short peptides. These enzymes are involved in glutathione metabolism and play critical roles in antioxidant defense, detoxification, and inflammation processes. Moreover, γ-GTs have been recently found to be involved in many physiological disorders, such as Parkinson's disease and diabetes. In this review, the main biochemical and structural properties of γ-GTs isolated from different sources, as well as their conformational stability and mechanism of catalysis, are described and examined with the aim of contributing to the discussion on their structure-function relationships. Possible applications of γ-glutamyltranspeptidases in different fields of biotechnology and medicine are also discussed.