| Title: | Characterization of the Phosphorylation Site of GRTH/DDX25 and Protein Kinase A Binding Interface Provides Structural Basis for the Design of a Non-Hormonal Male Contraceptive |
| Author(s): | Raju M; Hassan SA; Kavarthapu R; Anbazhagan R; Dufau ML; |
| Address: | "Section on Molecular Endocrinology, Division of Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, OIR/CIT, National Institutes of Health, Bethesda, MD, 20892-4510, USA. Center for Molecular Modeling, OIR/CIT, National Institutes of Health, Bethesda, MD, 20892-4510, USA. Section on Molecular Endocrinology, Division of Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, OIR/CIT, National Institutes of Health, Bethesda, MD, 20892-4510, USA. dufaum@mail.nih.gov" |
| DOI: | 10.1038/s41598-019-42857-9 |
| ISSN/ISBN: | 2045-2322 (Electronic) 2045-2322 (Linking) |
| Abstract: | "Gonadotropin Regulated Testicular Helicase (GRTH/DDX25), expressed in the male gonad, is essential for the completion of spermatogenesis. Our early studies revealed a missense mutation (R242H) of GRTH in 5.8% of Japanese patient population with azoospermia. Transfection of the mutant GRTH construct in COS-1 cells leads to loss of the 61 kDa cytoplasmic phospho-species. Mice with knock-in of the human GRTH mutation are sterile and lack sperm with normal androgen and mating behavior. These findings provide an avenue for the development of a non-hormonal male contraceptive. Using site directed mutagenesis and a site-specific phospho-antibody, we have identified T239, structurally adjacent to the patient's mutant site as the GRTH phospho-site. Molecular modelling provided structural basis for the role of R242 and other critical solvent-exposed residues at the GRTH/PKA interface (E165/K240/D237), on the control of GRTH phosphorylation at T239. Single or double mutations of these residues caused marked reduction or abolition of the phospho-form. These effects can be ascribed to critical disruptions of intramolecular H-bonds at the GRTH/PKA interface, which leads to modest but consequential structural changes that can affect PKA catalytic efficiency. Inhibition of phosphorylation may be achieved by small, drug-like molecules that bind to GRTH and reconfigure the GRTH/PKA interface" |
| Keywords: | "Animals COS Cells Catalysis Chlorocebus aethiops Contraceptive Agents, Male/chemistry/pharmacology Cyclic AMP-Dependent Protein Kinase Catalytic Subunits/genetics/metabolism Cyclic AMP-Dependent Protein Kinases/chemistry/genetics/*metabolism DEAD-box RNA;" |
| Notes: | "MedlineRaju, Murugananthkumar Hassan, Sergio A Kavarthapu, Raghuveer Anbazhagan, Rajakumar Dufau, Maria L eng Research Support, N.I.H., Intramural England 2019/05/02 Sci Rep. 2019 Apr 30; 9(1):6705. doi: 10.1038/s41598-019-42857-9" |
