title: Expression of protease-activated receptor-2 during embryonic development.
abstract: Protease-activated receptor-2 (PAR-2) is the second member of a novel family of G-protein-coupled receptors, activated through proteolytic cleavage within the extracellular domain to reveal a newly formed amino terminus that acts as a tethered ligand causing receptor activation. PAR-2 is expressed in a number of adult tissues, but its distribution during development has not been characterized. Knowledge of the tissue distribution of PAR-2 during development will provide clues as to its function(s) in vivo. In the current immunohistochemical study, a polyclonal antibody raised against a peptide corresponding to the post-cleavage amino terminal sequence of PAR-2 was used to localize PAR-2 expression in developing mouse tissues. In the developing central nervous system and cardiac muscle, PAR-2 expression was detectable at embryonic day 12 and persisted throughout embryogenesis. At embryonic day 14, PAR-2 expression was strong in peripheral nerves, but either weak or absent in skin, bone, skeletal muscle, and blood vessels. In embryonic day 17 and postnatal day 1 hindlimbs, however, PAR-2 staining was observed throughout the layers of the epidermis, in osteoblasts, muscle fibers, and in vascular smooth muscle and endothelium. The pattern of PAR-2 expression observed during embryonic development and the association of expression with differentiation in certain tissues suggest compelling physiological roles for this novel receptor.
authors.affiliation: Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia.
authors.forename: A L
authors.initials: AL
authors.lastname: Jenkins
authors.forename: C
authors.initials: C
authors.lastname: Chinni
authors.forename: M R
authors.initials: MR
authors.lastname: De Niese
authors.forename: B
authors.initials: B
authors.lastname: Blackhart
authors.forename: E J
authors.initials: EJ
authors.lastname: Mackie
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000918:Antibody Specificity; D019556:COS Cells; D004622:Embryo, Mammalian / Q000378:metabolism*; D005314:Embryonic and Fetal Development; D005434:Flow Cytometry; D015870:Gene Expression; D007150:Immunohistochemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D011817:Rabbits; D044464:Receptor, PAR-2; D018179:Receptors, Thrombin / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000276:immunology
chemical_list: D044464:Receptor, PAR-2; D018179:Receptors, Thrombin; D011993:Recombinant Fusion Proteins