Ziegelbauer K, Rudenko G, Kieft R, Overath P
Max-Planck-Institut für Biologie, Abteilung Membranbiochemie, Tübingen, Germany.
Mol Biochem Parasitol. 1995 Jan;69(1):53-63. doi: 10.1016/0166-6851(94)00194-r.
The genomic organization of a gene family for the invariant surface glycoprotein, ISG75 (invariant surface glycoprotein with a molecular mass of 75 kDa), from Trypanosoma brucei is described. In T. brucei strain 427 ISG75 genes are present in tandem arrays at two loci, A and B, containing 5 and 2 copies, respectively. At the 3'-end of locus A, a single gene was identified that encodes a structural isoform of ISG75. This isoform contains a unique amino-terminal domain, whereas the rest of the protein is nearly identical to the polypeptides encoded by the other genes. This isoform is transcribed into a stable mRNA, but the expression of the derived polypeptide was below the detection limit. The ISG75 gene clusters are present on chromosomal bands 9' and 10, supporting the hypothesis of Gottesdiener et al. [25] that these bands contain allelic chromosomes. The total number of ISG75 genes is strain dependent, but at least one copy of the unique isoform is present in every variant tested.
本文描述了布氏锥虫中分子量为75 kDa的不变表面糖蛋白ISG75（invariant surface glycoprotein，75 kDa）基因家族的基因组组织。在布氏锥虫427株中，ISG75基因以串联阵列形式存在于两个位点A和B，分别包含5个和2个拷贝。在位点A的3'端，鉴定出一个编码ISG75结构异构体的单一基因。该异构体包含一个独特的氨基末端结构域，而蛋白质的其余部分与其他基因编码的多肽几乎相同。该异构体被转录成稳定的mRNA，但衍生多肽的表达低于检测限。ISG75基因簇存在于染色体带9'和10上，支持了Gottesdiener等人[25]的假设，即这些带包含等位染色体。ISG75基因的总数取决于菌株，但在每个测试变体中至少存在一个独特异构体的拷贝。
