| First Author | Harris RM | Year | 2010 |
| Journal | Mamm Genome | Volume | 21 |
| Issue | 9-10 | Pages | 442-9 |
| PubMed ID | 20963592 | Mgi Jnum | J:166053 |
| Mgi Id | MGI:4839658 | Doi | 10.1007/s00335-010-9291-5 |
| Citation | Harris RM, et al. (2010) A missense mutation in LRR8 of RXFP2 is associated with cryptorchidism. Mamm Genome 21(9-10):442-9 |
| abstractText | Using genome-wide mutagenesis with N-ethyl-N-nitrosourea (ENU), a mouse mutant with cryptorchidism was identified. Genome mapping and exon sequencing identified a novel missense mutation (D294G) in Relaxin/insulin-like family peptide receptor 2 (Rxfp2). The mutation impaired testicular descent and resulted in decreased testis weight in Rxfp2 ( DG/DG ) mice compared to Rxfp2 (+/DG ) and Rxfp2 (+/+) mice. Testicular histology of the Rxfp2 ( DG/DG ) mice revealed spermatogenic defects ranging from germ cell loss to tubules with Sertoli-cell-only features. Genetic complementation analysis using a loss-of-function allele (Rxfp2 (-)) confirmed causality of the D294G mutation. Specifically, mice with one of each mutant allele (Rxfp2 ( DG/-)) exhibited decreased testis weight and failure of the testes to descend compared to their Rxfp2 (+/-) littermates. Total and cell-surface expression of mouse RXFP2 protein and intracellular cAMP accumulation were measured. Total expression of the D294G protein was minimally reduced compared to wild-type, but cell-surface expression was markedly decreased. When analyzed for cAMP accumulation, the EC50 was similar for cells transfected with wild-type and mutant RXFP2 receptor. However, the maximum cAMP response that the mutant receptor reached was greatly reduced compared to the wild-type receptor. In silico modeling of leucine rich repeats (LRRs) 7-9 indicated that aspartic acid 294 is located within the beta-pleated sheet of LRR8. We thus postulate that mutation of D294 results in protein misfolding and aberrant trafficking. The ENU-induced D294G mutation underscores the role of the INSL3/RXFP2-mediated pathway in testicular descent and expands the repertoire of mutations known to affect receptor trafficking and function. |
