title: Evolution of placental proteases.
abstract: The placenta is a critical organ in mammals required for the transport of nutrients from the mother to the fetus during gestation. Other critical functions of the placenta include hormone regulation and immune regulation. The origin of the mammals and early placenta is relatively recent in evolutionary terms, and consequently there are few placenta-specific genes. In two separate branches of mammalian evolution, gene duplications have given rise to two large families of protease genes that are expressed only by placental tissues. A family of aspartic protease genes is expressed only in artiodactyls, and a family of cysteine protease genes is expressed only in rodents. These genes have probably evolved to perform specific functions in the placenta that are carried out by broader specificity proteases in mammalian species that do not express these proteases.
authors.affiliation: Laboratory of Clinical Biochemistry, Nemours Childrens Clinic, Alfred I. duPont Hospital for Children, Wilmington, DE 19899, USA
authors.forename: Robert W
authors.initials: RW
authors.lastname: Mason
authors.forename: Deborah L
authors.initials: DL
authors.lastname: Stabley
authors.forename: Gina N
authors.initials: GN
authors.lastname: Picerno
authors.forename: Jennifer
authors.initials: J
authors.lastname: Frenck
authors.forename: Sixun
authors.initials: S
authors.lastname: Xing
authors.forename: Greg P
authors.initials: GP
authors.lastname: Bertenshaw
authors.forename: Katia
authors.initials: K
authors.lastname: Sol-Church
mesh_terms: D000818:Animals; D010450:Endopeptidases / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D019143:Evolution, Molecular; D005260:Female; D006801:Humans; D010802:Phylogeny; D010920:Placenta / Q000201:enzymology* / Q000502:physiology; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology
chemical_list: D011257:Pregnancy Proteins; D010450:Endopeptidases