title: Leptin receptors.
abstract: Leptin or obesity receptor (Ob-R) is a member of class I cytokine receptor family. Ob-R, expressed in six isoforms, is the product of alternative RNA splicing of db gene. According to its structural differences, the receptor's isoforms are divided into three classes: long, short, and secretory isoforms. A long, fully active isoform of Ob-Rb is expressed mainly in the hypothalamus, where it takes part in energy homeostasis and in the regulation of secretory organs' activity. Ob-Rb is also present on all types of immune cells, involved in innate and adaptive immunity. Short leptin isoforms (Ob-Ra, Ob-Rc, Ob-Rd, and Ob-Re) that contain box 1 motif are able to bind JAK kinases (Janus kinases) as well as to activate some other signal transduction cascades. A soluble isoform (Ob-Re) can regulate serum leptin concentration and serve as a carrier protein delivering the hormone to its membrane receptors and is able to transduce the signal into the cell. JAK/STAT pathway plays the major role in leptin signal transduction through membrane receptors. Among all Ob-R isoforms, only full-length isoform (Ob-Rb) is able to fully transduce activation signal into the cell.
authors.affiliation: Department of Laboratory Diagnostics, Warsaw Medical University, Warsaw, Poland. elgorska@litewska.edu.pl
authors.forename: Elzbieta
authors.initials: E
authors.lastname: Gorska
authors.forename: K
authors.initials: K
authors.lastname: Popko
authors.forename: A
authors.initials: A
authors.lastname: Stelmaszczyk-Emmel
authors.forename: O
authors.initials: O
authors.lastname: Ciepiela
authors.forename: A
authors.initials: A
authors.lastname: Kucharska
authors.forename: M
authors.initials: M
authors.lastname: Wasik
mesh_terms: D000818:Animals; D006801:Humans; D011110:Polymorphism, Genetic; D054411:Receptors, Leptin / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D015398:Signal Transduction
chemical_list: D054411:Receptors, Leptin