title: Localization and variable expression of G alpha(i2) in human endometrium and Fallopian tubes.
abstract: BACKGROUND
  Heterotrimeric G proteins take part in membrane-mediated cell signalling and have a role in hormonal regulation. This study clarifies the expression and localization of the G protein subunit G alpha(i2) in the human endometrium and Fallopian tube and changes in G alpha(i2) expression in human endometrium during the menstrual cycle.
  
  
  METHODS
  The expression of G alpha(i2) was identified by Polymerase chain reaction (PCR), and localization confirmed by immunostaining. Cyclic changes in G alpha(i2) expression during the menstrual cycle were evaluated by quantitative real-time PCR.
  
  
  RESULTS
  We found G alpha(i2) to be expressed in human endometrium, Fallopian tube tissue and in primary cultures of Fallopian tube epithelial cells. Our studies revealed enriched localization of G alpha(i2) in Fallopian tube cilia and in endometrial glands. We showed that G alpha(i2) expression in human endometrium changes significantly during the menstrual cycle, with a higher level in the secretory versus proliferative and menstrual phases (P < 0.05).
  
  
  CONCLUSIONS
  G alpha(i2) is specifically localized in human Fallopian tube epithelial cells, particularly in the cilia, and is likely to have a cilia-specific role in reproduction. Significantly variable expression of G alpha(i2) during the menstrual cycle suggests G alpha(i2) might be under hormonal regulation in the female reproductive tract in vivo.
authors.affiliation: Department of Pharmacology and Toxicology, University of Kuopio, Kuopio, Finland.
authors.forename: Kati S
authors.initials: KS
authors.lastname: Mönkkönen
authors.forename: Reza
authors.initials: R
authors.lastname: Aflatoonian
authors.forename: Kai-Fai
authors.initials: KF
authors.lastname: Lee
authors.forename: William S B
authors.initials: WS
authors.lastname: Yeung
authors.forename: Sai-Wah
authors.initials: SW
authors.lastname: Tsao
authors.forename: Jarmo T
authors.initials: JT
authors.lastname: Laitinen
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Tuckerman
authors.forename: T C
authors.initials: TC
authors.lastname: Li
authors.forename: Alireza
authors.initials: A
authors.lastname: Fazeli
mesh_terms: D000328:Adult; D004717:Endometrium / Q000378:metabolism*; D005187:Fallopian Tubes / Q000378:metabolism*; D005260:Female; D051960:GTP-Binding Protein alpha Subunit, Gi2 / Q000096:biosynthesis*; D005786:Gene Expression Regulation; D006801:Humans; D007150:Immunohistochemistry; D008597:Menstrual Cycle / Q000378:metabolism; D016133:Polymerase Chain Reaction
chemical_list: D051960:GTP-Binding Protein alpha Subunit, Gi2