title: Functional study of an aberrant splicing variant of the human luteinizing hormone (LH) receptor.
abstract: The luteinizing hormone receptor (LHR) is a member of a subfamily of G protein-coupled receptors that is characterized by its alternative splicing. In a previous study, we identified a splice site mutation of intron 6 (IVS6-3C>A) in a patient suffering from Leydig cell hypoplasia, which leads to aberrant splicing of LHR mRNA. In vitro expression analysis confirmed that this mutation results in the skipping of exon 7 in the mature mRNA of the LHR gene. In this study, we determined the impact of IVS6-3C>A on the RNA secondary structure and function of LHR-Del7. The three-dimensional structure of the leucine-rich repeats in LHR was predicted by molecular modeling. Radioactive ligand-binding assays verified that LHR-Del7 has no binding affinity for hCG. Furthermore, we detected negligible cAMP production in cells transfected with LHR-Del7. Cells co-expressing LHR-WT and LHR-Del7 were able to generate cAMP in response to hCG, but there was no significant difference between cells transfected with LHR-WT/vector and LHR-WT/LHR-Del7, although the variant was able to localize to cell surface, similar to wild-type receptor. These results indicated that LHR-Del7 does not have a dominant negative effect on LHR-WT cell surface expression, and although the pathological splicing variant LHR-Del7 was able to localize to cell membranes it failed to bind hCG and had no effect on wild-type LHR.
authors: State Key Laboratory of Medical Genomics, Molecular Medical Center,  Shanghai Institute of Endocrinology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, People's Republic of  China.
authors: Bing
authors: B
authors: Han
authors: Zhi-quan
authors: ZQ
authors: Wang
authors: Li-qiong
authors: LQ
authors: Xue
authors: Jun-hua
authors: JH
authors: Ma
authors: Wei
authors: W
authors: Liu
authors: Bing-li
authors: BL
authors: Liu
authors: Jia-jun
authors: JJ
authors: Wu
authors: Chun-ming
authors: CM
authors: Pan
authors: Xia
authors: X
authors: Chen
authors: Shuang-xia
authors: SX
authors: Zhao
authors: Ying-li
authors: YL
authors: Lu
authors: Wan-ling
authors: WL
authors: Wu
authors: Jie
authors: J
authors: Qiao
authors: Huai-dong
authors: HD
authors: Song
mesh_terms: D015153:Blotting, Western; D002460:Cell Line; D005091:Exons / Q000235:genetics; D005455:Fluorescent Antibody Technique; D006801:Humans; D018613:Microscopy, Confocal; D009690:Nucleic Acid Conformation; D012326:RNA Splicing / Q000235:genetics*; D011974:Receptors, LH / Q000235:genetics*
chemical_list: D011974:Receptors, LH