Figlewicz D A, Delattre O, Guellaen G, Krizus A, Thomas G, Zucman J, Rouleau G A
Department of Neurology, Montreal General Hospital, Canada.
Genomics. 1993 Aug;17(2):299-305. doi: 10.1006/geno.1993.1325.
gamma-Glutamyl transpeptidase (GGT; EC 2.3.2.2) is a membrane-associated enzyme that plays a role in the metabolism of glutathione and in the transpeptidation of amino acids; changes in GGT activity may reflect preneoplastic or toxic conditions in the liver or kidney. In contrast to the rat, in which GGT is represented by a single gene, at least four GGT genomic sequences have been identified in man and two of these have been localized to two distinct regions of chromosome 22. To characterize this gene/pseudogene family further, we have used somatic cell hybrids to map GGT by hybridization with probes from a human kidney GGT cDNA clone and by amplification of 3' GGT sequence by PCR. We clearly map three GGT loci to chromosome 22: two loci between the centromere and the breakpoint cluster region (BCR) gene and one locus telomeric to the BCR gene. In addition, we have been able to identify GGT-related sequences on chromosomes 18, 19, and 20.
γ-谷氨酰转肽酶（GGT；EC 2.3.2.2）是一种与膜相关的酶，在谷胱甘肽代谢和氨基酸转肽过程中起作用；GGT活性的变化可能反映肝脏或肾脏的肿瘤前病变或中毒情况。与大鼠不同，大鼠的GGT由单一基因代表，而在人类中已鉴定出至少四个GGT基因组序列，其中两个已定位到22号染色体的两个不同区域。为了进一步表征这个基因/假基因家族，我们利用体细胞杂种通过与人肾GGT cDNA克隆的探针杂交以及通过PCR扩增3' GGT序列来对GGT进行定位。我们清楚地将三个GGT基因座定位到22号染色体：两个基因座在着丝粒和断裂点簇区域（BCR）基因之间，一个基因座在BCR基因的端粒侧。此外，我们已经能够在18号、19号和20号染色体上鉴定出与GGT相关的序列。
