Genomics and genetics of gonadotropin beta-subunit genes: Unique FSHB and duplicated LHB/CGB loci

Institute of Molecular and Cell Biology, University of Tartu, Riia St. 23, 51010 Tartu, Estonia.
Molecular and Cellular Endocrinology (Impact Factor: 4.24). 11/2010; 329(1-2):4-16. DOI: 10.1016/j.mce.2010.04.024
Source: PubMed

ABSTRACT The follicle stimulating hormone (FSH), luteinizing hormone (LH) and chorionic gonadotropin (HCG) play a critical role in human reproduction. Despite the common evolutionary ancestry and functional relatedness of the gonadotropin hormone beta (GtHB) genes, the single-copy FSHB (at 11p13) and the multi-copy LHB/CGB genes (at 19q13.32) exhibit locus-specific differences regarding their genomic context, evolution, genetic variation and expressional profile. FSHB represents a conservative vertebrate gene with a unique function and it is located in a structurally stable gene-poor region. In contrast, the primate-specific LHB/CGB gene cluster is located in a gene-rich genomic context and demonstrates an example of evolutionary young and unstable genomic region. The gene cluster is shaped by a constant balance between selection that acts on specific functions of the loci and frequent gene conversion events among duplicons. As the transcription of the GtHB genes is rate-limiting in the assembly of respective hormones, the genomic and genetic context of the FSHB and the LHB/CGB genes largely affects the profile of the hormone production.

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Available from: Kristiina Rull, Jul 28, 2015
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    • "The unique functions and receptor-binding capacity of each of these hormones stem from differences among the b subunits (Table 1). Transcription of the b-subunit is the rate-limiting step in LH and CG production (Nagirnaja et al., 2010). The genes for the LH and hCG b subunits are located within a cluster of seven similar sequences on human chromosome 19q13.32 "
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    Molecular and Cellular Endocrinology 12/2013; 383(1-2). DOI:10.1016/j.mce.2013.12.009 · 4.24 Impact Factor
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    • "The structural and functional properties of the subunits are determined by six cystine bonds and six oligosaccharide chains (two N-linked, four O-linked) in hCGb and five cystine bonds and two N-linked carbohydrates in the a-subunit (Morgan et al., 1975; Lapthorn et al., 1994). The chorionic gonadotrophin beta (CGB) genes encoding the hCG b-subunit (145 aa) have evolved in the primate lineage by serial duplications of the ancestral LH b-subunit coding gene (LHB) (Maston and Ruvolo, 2002; Hallast et al., 2008; Nagirnaja et al., 2010). In humans, the common gene cluster for LHB and six CGB genes is located at 19q13.32 (Policastro et al., 1986). "
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