Relaxin gene expression in human ovaries and the predicted structure of a human preprorelaxin by analysis of cDNA clones.

Abstract

In earlier studies we identified in a human genomic library a gene (human relaxin gene HI) coding for a relaxin-related peptide. We now have evidence that the human genome possesses an additional relaxin-related gene (designated human relaxin gene H2) which appears to be selectively expressed in the ovary during pregnancy. Nucleotide sequence analysis revealed striking differences in the predicted structures of relaxin encoded by these two genes. Chemical synthesis of biologically active relaxin based on the sequence obtained from ovarian cDNA clones confirmed that the expressed gene (H2) encodes an authentic human relaxin. The expressed gene appears to be transcribed into two different sized mRNAs and preliminary evidence suggests that the mRNA transcripts possess different 3'-untranslated regions. There was no evidence for the expression of human relaxin gene HI in the ovary and so far it is unclear whether gene Hl is expressed in another tissue or whether it represents a pseudogene. From the sequence data presented here it will now be possible to construct oligonucleotide probes and raise antibodies against synthetic peptides which could then be used to identify sites of relaxin biosynthesis and specifically quantitate the expression from either the Hl or H2 relaxin genes.

Analysis of the 5'-upstream regions of the human relaxin H1 and H2 genes and their chromosomal localization on chromosome 9p24.1 by radiation hybrid and breakpoint mapping

“…Both relaxin genes are actively transcribed and translated in several reproductive tissues (Bryant-Greenwood & Schwabe 1994), however, only the relaxin H2 is expressed in the corpus luteum (Hudson et al 1984). The reason for this differential expression of the relaxin genes is unknown.…”

“…In the human there are two non-allelic genes for relaxin, termed H1 and H2 that encode two biologically active relaxin peptides (Crawford et al 1984). Relaxin is best known as an endocrine hormone produced by the ovary and acting on the mammalian reproductive system to cause uterine quiescence and to remodel connective tissues, thereby facilitating the birth process (Bryant-Greenwood & Schwabe 1994).…”

“…Relaxin is best known as an endocrine hormone produced by the ovary and acting on the mammalian reproductive system to cause uterine quiescence and to remodel connective tissues, thereby facilitating the birth process (Bryant-Greenwood & Schwabe 1994). The systemic relaxin acting in this way is the H2 form and the only relaxin produced by the human corpus luteum (Hudson et al 1984). It has been shown, however, that relaxins are also autocrine/paracrine hormones in a number of other tissues such as prostate (Hansell et al 1991), placenta (Sakbun et al 1990), endometrium, decidua (Bryant-Greenwood et al 1993) and mammary gland (Tashima et al 1994).…”

Identification of Relaxin-3/INSL7 as a Ligand for GPCR142

“…Recently, two leucine-rich repeat-containing G-protein-coupled receptors (LGRs), 1 LGR7 and LGR8 (2,3), have been identified as the receptors for relaxin (3)(4)(5)(6)(7).…”

Serum relaxin levels affect the in vivo properties of some but not all tendons in normally menstruating young women

“…It was first described by Frederick Hisaw in 1926(Hisaw, 1926, who showed in animals that ligaments relaxed following injection with pregnant guinea-pig serum. In humans to date, three different isoforms of relaxin have been described, namely H1, H2 and H3 (Hudson et al 1983(Hudson et al , 1984Bathgate et al 2002, respectively). However, relaxin is not solely a pregnancyrelated hormone; in non-pregnant women, relaxin has been detected during both the follicular and the luteal phases of the menstrual cycle (Wreje et al 1995).…”