GNAI2 Geninde İki Aday Polimorfizm

Amaç: GNAI2 geninin 193 numaralı kodonunda bir hipofiz tümöründe ilk kez saptanmış olan bir mutasyonun polimorfizm olma olasılığının incelenmesi. Hastalar ve Yöntem: Kandan elde edilen DNA’lar GNAI2 geninin beşinci ve altıncı eksonları ile aralarındaki intron bölgesini içerecek şekilde Polimeraz Zincir Tepkimesi PZT ile çoğaltıldı. PZT ürünleri Tek Sarmal Konformasyon Polimorfizmi SSCP yöntemiyle mutasyon belirleme MDE ve poliakrilamit jellerinde incelendi. Seçilen bazı örneklerin otomatik DNA analizi gerçekleştirildi. Bulgular: SSCP analizinde farklı örnekçe belirlenen iki örneğin otomatik DNA dizi analizlerinde, 193 numaralı kodonda mutasyon olmadığı ancak GNAI2 geninin beşinci ve altincı eksonları arasındaki intron bölgesinde bir C/T C20151 değişikliğinin olduğu saptandı. Sonuç: Bulgularımız GNAI2 geninin 193 numaralı kodonunda daha önce belirlenen değişikliğin polimorfizm olma olasılığını desteklememektedir.

Two Candidate Polymorphisms of The Gnai2 Gene

Objective: To investigate whether a variation in codon 193 of the GNAI2 gene previously determined in a recurrent somatotroph adenoma is a polymorphism. Patients and Methods: Genomic DNA extracted from blood was amplified for the fifth and sixth exons and the intervening sequence of the GNAI2 gene with Polymerase Chain Reaction PCR . PCR products were analyzed with Single Strand Conformation Polymorphism SSCP on Mutation Detection Enhancement MDE and polyacrylamide gels. Selected samples were subjected to direct sequencing. Results: In total, two samples exhibited abnormal banding patterns in SSCP analysis. DNA sequencing of the PCR products revealed no mutations in codon 193. On the other hand, these samples exhibited a C/T C20151 variation in the intervening sequence between exons 5 and 6 of the GNAI2 gene. Conclusions: Our results do not support the possibility of a polymorphism in codon 193 of the GNAI2 gene.

Keywords:

G protein, polymorphism,

PDF

___

Hepler JR., Gilman AG. G-proteins. Trends Bioch Sci 1992; 17: 383-387.

Rens-Domiano S, Hamm HE. Structural and functional-relationships of heterotrimeric G-proteins. FASEB J 1995; 9: 1059-1069.

Küçükkaya B, Kan B. Heterotrimerik G proteinleri. Turk J Biochem 2007; 32: 39-50.

Koelle MR. A new family of G-protein regulators - The RGS proteins. Curr Opin Cell Biol 1997; 9: 143-147.

Shenker A. Activating mutations in G protein-coupled signaling pathways as a cause of endocrine disease. GGH J 1996; 12: 33-38.

Spiegel AM. Defects in G protein-coupled signal transduction in human disease. Annu Rev Physiol 1996; 58: 143-170.

Radhika V, Dhanasekaran N. Transforming G proteins. Oncogene 2001; 20: 1607-1614.

Lania A, Mantovani G, Spada A. G protein mutations in endocrine diseases. Eur J Endocrinol 2001; 145: 543-559.

Shi MM. Enabling large-scale pharmacogenetic studies by high-throughput mutation detection and genotyping technologies. Clinical Chem 2001; 47: 164-172.

Siffert W. G protein polymorphisms in hypertension, atherosclerosis, and diabetes. Annu Rev Med 2005; 56: 17-28.

Bachmann HS, Lieb B, Bonnet U, et al. Influence of the 393T>C polymorphism of the GNAS1 gene on the intensity of opiate withdrawal. Pharmacopsychiatry. 2011; 44: 159-160.

Klenke S, Siffert W. SNPs in genes encoding G proteins in pharmacogenetics. Pharmacogenomics. 2011; 12: 633-654.

Gutkind JS. The pathways connecting G protein-coupled receptors to the nucleus through divergent mitogen-activated protein kinase cascades. J Biol Chem 1998; 273: 1839-1842.

Kan B, Esapa C, Sipahi T, et al. G protein mutations in pituitary tumors: a study on Turkish patients. Pituitary 2003; 6: 75-80.

Orita M, Iwahana H, Kanazawa H, Hayashi K, Sekiya T. Detection of polymorphisms of human DNA by gel electrophoresis as single-strand conformation polymorphisms. Proc Natl Acad Sci USA 1989; 86: 2766-2770.

Chakravarti A.Single nucleotide polymorphisms.. to a future of genetic medicine. Nature 2001; 409: 822-823.

Bastepe M, Pincus JE, Sugimoto T et al. Positional dissociation between the genetic mutation responsible for pseudohypoparathyroidism type Ib and the associated methylation defect at exon A/B: evidence for a long-range regulatory element within the imprinted GNAS1 locus. Hum Mol Genet 2001; 10: 1231-1241.

Sedlacek K, Fischer M, Erdmann J, et al. Relation of the G protein beta(3)-subunit polymorphism with left ventricle structure and function. Hypertension 2002; 40: 162-167.

Garcia SI, Porto PI, Dieuzeude G. et al. Thyrotropin-releasing hormone receptor (TRHR) gene is associated with essential hypertension. Hypertension 2001; 38: 683-687.

Stanton T, Inglis G.C, Padmanabhan S, Dominiczak AF, Jardine AG, Connell JMC. Variation at the beta-1 adrenoceptor gene locus affects left ventricular mass in renal failure. J Nephrol 2002; 15: 512-518.

Fukunaga K, Ishii S, Asano K et al. Single nucleotide polymorphism of human platelet-activating factor receptor impairs G-protein activation. J Biol Chem 2001; 276: 43025-43030.

Mason DA, Moore J, Green SA, Liggett S B. A gain-of-function polymorphism in a G-protein coupling domain of the human beta(1)-adrenergic receptor. J Biol Chem 1999; 274: 12670-12674.

Small KM, Brown KM, Forbes SL, Liggett SB. Polymorphic deletion of three intracellular acidic residues of the alpha(2B)-adrenergic receptor decreases G protein-coupled receptor kinase-mediated phosphorylation and desensitization. J Biol Chem 2001; 276: 4917-4922.