Molecular Human Reproduction, Vol. 8, No. 10, 887-892,
October 2002
© 2002 European Society of Human Reproduction and Embryology
Reproductive endocrinology |
Functional study of a recombinant form of human LHß-subunit variant carrying the Gly102Ser mutation found in Asian populations
1 Department of Physiology, Institute of Biomedicine, University of Turku, Kiinamyllynkatu 10, FIN-20520 Turku, Finland, 2 Department of Clinical Biochemistry, Statens Serum Institute, DK-2300 Copenhagen, Denmark and 3 Department of Biological Sciences, Florida International University, Miami, FL 33199, USA
Genetic variants of human LH caused by amino acid replacements in the ß-subunit have been demonstrated to affect reproductive function. Occurrence of a G1502A substitution in the LHß gene leading to Gly102Ser replacement of the LHß protein has been found to be associated with infertility in the Singapore Chinese population. In the present study, a search for this LHß allele from 383 DNA samples from different continents, using a PCR-based strategy, demonstrated its total absence in these populations. Functional properties of the variant (V) (Gly102Ser substitution) LHß subunit were assessed using a recombinant (r) form of V-LH produced in HEK293 cells, in comparison with wild-type (WT) LH or hCG. The synthesized V-LH was purified by a single step of immunoaffinity chromatography, and it had a molecular weight of 30 kDa as determined by SDS–PAGE. The affinities of the WT-hCG and rV-LH in mouse Leydig tumour (mLT-1) cell LH receptor binding were similar, with Kd values of 0.140 ± 0.03 and 0.156 ± 0.01 nmol/l respectively. Likewise, the effects of WT- and V-rLH preparations on mLT-1 cell cAMP and progesterone production were concentration-dependent and with similar biopotencies. In addition, HEK293 cells expressing the human LH receptor documented similar dose-dependent increases in inositol phosphate production by the two rLH forms. In conclusion, these findings demonstrate that Gly102Ser mutation of the LHß gene does not affect receptor binding and bioactivity of the hormone, when tested in vitro.
functional study/luteinizing hormone/variant
4 To whom correspondence should be addressed. E-mail: ilpo.huhtaniemi{at}utu.fi
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  A. P N Themmen An update of the pathophysiology of human gonadotrophin subunit and receptor gene mutations and polymorphisms Reproduction, September 1, 2005; 130(3): 263 - 274. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. Lamminen, P. Jokinen, M. Jiang, P. Pakarinen, H. Simonsen, and I. Huhtaniemi Human FSH{beta} subunit gene is highly conserved Mol. Hum. Reprod., August 1, 2005; 11(8): 601 - 605. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Jiang, M.-L. Savontaus, H. Simonsen, C. Williamson, R. Mullenbach, J. Gromoll, N. Terwort, M. Alevizaki, and I. Huhtaniemi Absence of the genetic variant Val79Met in human chorionic gonadotropin-beta gene 5 in five European populations Mol. Hum. Reprod., October 1, 2004; 10(10): 763 - 766. [Abstract] [Full Text] [PDF]
|
|