Beta podjedinica luteinizirajućeg hormona ili alutropinska podjedinica beta ili LHβ je polipeptid koji je, skupa sa glikoproteinskog hormonat zajednički za sve gonadotropinske hormone, a stvara reproduktivne signalizirajuće moleule luteinizirajućeg hormona. Kod ljudi, njegovu sintezu kodira genLHB.[1][2]
Beta podjedinica luteinizirajućeg hormona kodirana je jednim genom kod svih sisara. U primata ovaj gen nalazi se u klasteru koji je nastao umnožavanjem gena, a uključuje i više redundantnih gena koji kodiraju beta podjedinicu horionskog gonadotropina, kao i nekoliko nefunkcionalnih pseudogena. Kod ljudi su oni povezani na poziciji 19q13.3 hromosoma 19.[2] U kopitara, beta podjedinica polipeptida luteinizirajućeg hormona i horionski gonadotropin imaju identične skeletne sekvence, a razlikuju se samo po bočnim lancima ugljikohidrata, a proizvod su jednog gena.[3]
Ovaj gen je član porodice glikoproteinskih hormona beta lanca i kodira beta podjedinicu luteinizirajućeg hormona (LH). Glikoproteinski hormoni su heterodimeri koji se sastoje od zajedničke podjedinice alfa i jedinstvene beta podjedinice (ovog proteina) koja daje biološku specifičnost. LH se ispoljava u hipofizi i podstiče spermatogenezu i ovulaciju, stimulirajući testise i jajnike na sintezu steroida.[2]
Mutacije u ovom genu povezane su sa hipogonadizmom koji karakterizira neplodnost i pseudohermafroditizam.[2]
Sherman GB, Wolfe MW, Farmerie TA, Clay CM, Threadgill DS, Sharp DC, Nilson JH (juni 1992). "A single gene encodes the beta-subunits of equine luteinizing hormone and chorionic gonadotropin". Mol. Endocrinol. 6 (6): 951–9. doi:10.1210/me.6.6.951. PMID1379674.
Keutmann HT, Hua QX, Weiss MA (1992). "Structure of a receptor-binding fragment from human luteinizing hormone beta-subunit determined by [1H]- and [15N]nuclear magnetic resonance spectroscopy". Mol. Endocrinol. 6 (6): 904–13. doi:10.1210/me.6.6.904. PMID1495492.
Weiss J, Axelrod L, Whitcomb RW, etal. (1992). "Hypogonadism caused by a single amino acid substitution in the beta subunit of luteinizing hormone". N. Engl. J. Med. 326 (3): 179–83. doi:10.1056/NEJM199201163260306. PMID1727547.
Weisshaar G, Hiyama J, Renwick AG, Nimtz M (1991). "NMR investigations of the N-linked oligosaccharides at individual glycosylation sites of human lutropin". Eur. J. Biochem. 195 (1): 257–68. doi:10.1111/j.1432-1033.1991.tb15702.x. PMID1991473.
Jameson JL, Lindell CM, Habener JF (1986). "Evolution of different transcriptional start sites in the human luteinizing hormone and chorionic gonadotropin beta-subunit genes". DNA. 5 (3): 227–34. doi:10.1089/dna.1986.5.227. PMID2424697.
Closset J, Hennen G, Lequin RM (1973). "Human luteinizing hormone. The amino acid sequence of the subunit". FEBS Lett. 29 (2): 97–100. doi:10.1016/0014-5793(73)80534-4. PMID4719207.
Talmadge K, Vamvakopoulos NC, Fiddes JC (1984). "Evolution of the genes for the beta subunits of human chorionic gonadotropin and luteinizing hormone". Nature. 307 (5946): 37–40. doi:10.1038/307037a0. PMID6690982.
Beitins IZ, Axelrod L, Ostrea T, etal. (1981). "Hypogonadism in a male with an immunologically active, biologically inactive luteinizing hormone: characterization of the abnormal hormone". J. Clin. Endocrinol. Metab. 52 (6): 1143–9. doi:10.1210/jcem-52-6-1143. PMID6785294.
Berger P, Kranewitter W, Madersbacher S, etal. (1994). "Eutopic production of human chorionic gonadotropin beta (hCG beta) and luteinizing hormone beta (hLH beta) in the human testis". FEBS Lett. 343 (3): 229–33. doi:10.1016/0014-5793(94)80561-X. PMID7513655.
Keutmann HT, Rubin DA (1993). "A subunit interaction site in human luteinizing hormone: identification by photoaffinity cross-linking". Endocrinology. 132 (3): 1305–12. doi:10.1210/en.132.3.1305. PMID7679977.
Muyan M, Furuhashi M, Sugahara T, Boime I (1997). "The carboxy-terminal region of the beta-subunits of luteinizing hormone and chorionic gonadotropin differentially influence secretion and assembly of the heterodimers". Mol. Endocrinol. 10 (12): 1678–87. doi:10.1210/me.10.12.1678. PMID8961276.
Roy AC, Liao WX, Chen Y, etal. (1997). "Identification of seven novel mutations in LH beta-subunit gene by SSCP". Mol. Cell. Biochem. 165 (2): 151–3. doi:10.1007/bf00229477. PMID8979264.
Liao WX, Roy AC, Chan C, etal. (1998). "A new molecular variant of luteinizing hormone associated with female infertility". Fertil. Steril. 69 (1): 102–6. doi:10.1016/S0015-0282(97)00445-7. PMID9457942.
Elter K, Erel CT, Cine N, etal. (1999). "Role of the mutations Trp8 => Arg and Ile15 => Thr of the human luteinizing hormone beta-subunit in women with polycystic ovary syndrome". Fertil. Steril. 71 (3): 425–30. doi:10.1016/S0015-0282(98)00491-9. PMID10065776.