Signal transduction pathways activated by insulin-like peptide 5 at the relaxin family peptide RXFP4 receptor.

摘要: Background and purpose Insulin-like peptide 5 (INSL5) is a two-chain, three-disulfide-bonded of the insulin/relaxin superfamily, uniquely expressed in enteroendocrine L-cells colon. It cognate ligand relaxin family RXFP4 receptor that mainly colorectum enteric nervous system. This study identifies new signalling pathways activated by INSL5 acting on receptors. Experimental approach INSL5/RXFP4 was investigated using AlphaScreen® proximity assays. Recruitment Gαi/o proteins receptors determined rescue Pertussis toxin (PTX)-inhibited cAMP ERK1/2 responses following transient transfection PTX-insensitive C351I mutants. Cell proliferation studied with bromodeoxyuridine. interactions β-arrestins, GPCR kinase 2 (GRK2), KRas Rab5a assessed real-time BRET. Gene expression quantitative PCR. Insulin release measured HTRF intracellular Ca2+ flux monitored Flexstation® Fluo-4-AM. Key results inhibited forskolin-stimulated accumulation increased phosphorylation ERK1/2, p38MAPK, Akt Ser473 , Thr308 S6 ribosomal protein. were abolished PTX rescued mGαoA mGαoB mGαi2 to lesser extent mGαi1 mGαi3 . interacted GRK2 moved towards away from KRas, indicating internalisation activation. glucose-stimulated insulin secretion mobilisation MIN6 insulinoma cells NCI-H716 cells. Conclusions implications Knowledge at essential for understanding biological roles this novel gut hormone. Linked articles article part themed section Recent Progress Understanding Relaxin Family Peptides their Receptors. To view other visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.10/issuetoc.