title: The orphan G protein-coupled receptor 161 is required for left-right patterning.
abstract: Gpr161 (also known as RE2) is an orphan G protein-coupled receptor (GPCR) that is expressed during embryonic development in zebrafish. Determining its biological function has proven difficult due to lack of knowledge regarding its natural or synthetic ligands. Here, we show that targeted knockdown of gpr161 disrupts asymmetric gene expression in the lateral plate mesoderm, resulting in aberrant looping of the heart tube. This is associated with elevated Ca(2+) levels in cells lining the Kupffer's vesicle and normalization of Ca(2+) levels, by over-expression of ncx1 or pmca-RNA, is able to partially rescue the cardiac looping defect in gpr161 knockdown embryos. Taken together, these data support a model in which gpr161 plays an essential role in left-right (L-R) patterning by modulating Ca(2+) levels in the cells surrounding the Kupffer's vesicle.
authors.affiliation: Weis Center for Research, Geisinger Clinic, Danville, PA 17822, USA. tleung1@geisinger.edu
authors.forename: Tinchung
authors.initials: T
authors.lastname: Leung
authors.forename: Jasper E
authors.initials: JE
authors.lastname: Humbert
authors.forename: Anna M
authors.initials: AM
authors.lastname: Stauffer
authors.forename: Kathryn E
authors.initials: KE
authors.lastname: Giger
authors.forename: Hui
authors.initials: H
authors.lastname: Chen
authors.forename: Huai-Jen
authors.initials: HJ
authors.lastname: Tsai
authors.forename: Chuan
authors.initials: C
authors.lastname: Wang
authors.forename: Tooraj
authors.initials: T
authors.lastname: Mirshahi
authors.forename: Janet D
authors.initials: JD
authors.lastname: Robishaw