Growth hormone 2 explained

Growth hormone 2 (GH2), also known more commonly as placental growth hormone (PGH) or growth hormone variant (GH-V), is a protein that in humans is encoded by the GH2 gene.^{[1] [2]} It is produced by and secreted from the placenta during pregnancy, and becomes the predominant form of growth hormone (GH) in the body during this time.^{[3] [4]} Its cogener is growth hormone 1 (GH1), or pituitary growth hormone.

The protein encoded by this gene is a member of the somatotropin/prolactin family of hormones, playing an important role in growth control. The gene, along with four other related genes, is located at the growth hormone locus on chromosome 17, where they are interspersed in the same transcriptional orientation; an arrangement that is thought to have evolved through a series of gene duplications. The five genes share a remarkably high degree of sequence identity. Alternative splicing generates additional isoforms of each of the five growth hormones, leading to further diversity and the potential for specialization. As in the case of its pituitary counterpart, growth hormone 1, the predominant isoform of this particular family member shows similar somatogenic activity with reduced lactogenic activity. Mutations in this gene lead to placental growth hormone/lactogen deficiency.

See also

• Growth hormone
• Somatotropin family

Further reading

• MacLeod JN, Lee AK, Liebhaber SA, Cooke NE . Developmental control and alternative splicing of the placentally expressed transcripts from the human growth hormone gene cluster . J. Biol. Chem. . 267 . 20 . 14219–26 . 1992 . 10.1016/S0021-9258(19)49700-7 . 1378436 . free .
• Baumann G, Dávila N, Shaw MA, etal . Binding of human growth hormone (GH)-variant (placental GH) to GH-binding proteins in human plasma . J. Clin. Endocrinol. Metab. . 73 . 6 . 1175–9 . 1992 . 1955498 . 10.1210/jcem-73-6-1175 .
• Vnencak-Jones CL, Phillips JA . Hot spots for growth hormone gene deletions in homologous regions outside of Alu repeats . Science . 250 . 4988 . 1745–8 . 1991 . 1980158 . 10.1126/science.1980158 .
• Frankenne F, Scippo ML, Van Beeumen J, etal . Identification of placental human growth hormone as the growth hormone-V gene expression product . J. Clin. Endocrinol. Metab. . 71 . 1 . 15–8 . 1990 . 2196278 . 10.1210/jcem-71-1-15 .
• Igout A, Scippo ML, Frankenne F, Hennen G . Cloning and nucleotide sequence of placental hGH-V cDNA . Arch. Int. Physiol. Biochim. . 96 . 1 . 63–7 . 1988 . 2460050 . 10.3109/13813458809079626 .
• Chen EY, Liao YC, Smith DH, etal . The human growth hormone locus: nucleotide sequence, biology, and evolution . Genomics . 4 . 4 . 479–97 . 1989 . 2744760 . 10.1016/0888-7543(89)90271-1 .
• Cooke NE, Ray J, Emery JG, Liebhaber SA . Two distinct species of human growth hormone-variant mRNA in the human placenta predict the expression of novel growth hormone proteins . J. Biol. Chem. . 263 . 18 . 9001–6 . 1988 . 10.1016/S0021-9258(18)68407-8 . 3379057 . free .
• George DL, Phillips JA, Francke U, Seeburg PH . The genes for growth hormone and chorionic somatomammotropin are on the long arm of human chromosome 17 in region q21 to qter . Hum. Genet. . 57 . 2 . 138–41 . 1981 . 6262212 . 10.1007/BF00282009 . 22391019 .
• Kidd VJ, Saunders GF . Linkage arrangement of human placental lactogen and growth hormone genes . J. Biol. Chem. . 257 . 18 . 10673–80 . 1982 . 10.1016/S0021-9258(18)33875-4 . 6286668 . free .
• Harper ME, Barrera-Saldaña HA, Saunders GF . Chromosomal localization of the human placental lactogen-growth hormone gene cluster to 17q22-24 . Am. J. Hum. Genet. . 34 . 2 . 227–34 . 1982 . 7072716 . 1685277 .
• Seeburg PH . The human growth hormone gene family: nucleotide sequences show recent divergence and predict a new polypeptide hormone . DNA . 1 . 3 . 239–49 . 1983 . 7169009 . 10.1089/dna.1.1982.1.239.
• Owerbach D, Rutter WJ, Martial JA, etal . Genes for growth hormone, chorionic somatommammotropin, and growth hormones-like gene on chromosome 17 in humans . Science . 209 . 4453 . 289–92 . 1980 . 7384802 . 10.1126/science.7384802 . 1980Sci...209..289O .
• Sundström M, Lundqvist T, Rödin J, etal . Crystal structure of an antagonist mutant of human growth hormone, G120R, in complex with its receptor at 2.9 A resolution . J. Biol. Chem. . 271 . 50 . 32197–203 . 1997 . 8943276 . 10.1074/jbc.271.50.32197 . free .
• Melen L, Hennen G, Dullaart RP, etal . Both pituitary and placental growth hormone transcripts are expressed in human peripheral blood mononuclear cells (PBMC) . Clin. Exp. Immunol. . 110 . 2 . 336–40 . 1997 . 9367422 . 10.1111/j.1365-2249.1997.tb08337.x. 2265512 .
• Boguszewski CL, Svensson PA, Jansson T, etal . Cloning of two novel growth hormone transcripts expressed in human placenta . J. Clin. Endocrinol. Metab. . 83 . 8 . 2878–85 . 1998 . 10.1210/jcem.83.8.5017 . 9709963 . 1050988 . free .
• Untergasser G, Hermann M, Rumpold H, Berger P . Complex alternative splicing of the GH-V gene in the human testis . Eur. J. Endocrinol. . 139 . 4 . 424–7 . 1998 . 9820620 . 10.1530/eje.0.1390424 . 18836999 .
• Graichen R, Liu D, Sun Y, etal . Autocrine human growth hormone inhibits placental transforming growth factor-beta gene transcription to prevent apoptosis and allow cell cycle progression of human mammary carcinoma cells . J. Biol. Chem. . 277 . 29 . 26662–72 . 2002 . 11994274 . 10.1074/jbc.M109931200 . free .
• Silva CM, Kloth MT, Lyons CE, etal . Intracellular signaling by growth hormone variant (GH-V) . Growth Horm. IGF Res. . 12 . 5 . 374–80 . 2003 . 12213191 . 10.1016/S1096-6374(02)00048-5 .
• Strausberg RL, Feingold EA, Grouse LH, etal . Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences . Proc. Natl. Acad. Sci. U.S.A. . 99 . 26 . 16899–903 . 2003 . 12477932 . 10.1073/pnas.242603899 . 139241 . 2002PNAS...9916899M . free .

External links

• Human Growth Hormone

Notes and References

1. Barsh GS, Seeburg PH, Gelinas RE . The human growth hormone gene family: structure and evolution of the chromosomal locus . Nucleic Acids Res . 11 . 12 . 3939–58 . Aug 1983 . 6306568 . 326017 . 10.1093/nar/11.12.3939 .
2. Web site: Entrez Gene: GH2 growth hormone 2.
3. Handwerger S, Freemark M . The roles of placental growth hormone and placental lactogen in the regulation of human fetal growth and development . J. Pediatr. Endocrinol. Metab. . 13 . 4 . 343–56 . 2000 . 10776988 . 10.1515/jpem.2000.13.4.343. 28778529 .
4. Lacroix MC, Guibourdenche J, Frendo JL, Muller F, Evain-Brion D . Human placental growth hormone--a review . Placenta . 23 Suppl A . S87–94 . 2002 . 11978064 . 10.1053/plac.2002.0811 .