Joshua G W
London School of Hygiene and Tropical Medicine, Department of Infectious and Tropical Diseases, Keppel Street, WC1E 7HT, London, UK.
Mol Biochem Parasitol. 2001 Apr 6;113(2):223-32. doi: 10.1016/s0166-6851(01)00221-3.
To investigate the function of the enzyme leucine aminopeptidase in nematodes, a Caenorhabditis elegans leucine aminopeptidase gene identified in the genome sequence was functionally analysed by transfection of a leucine aminopeptidase beta-galactosidase reporter construct and characterisation of a null mutant. The leucine aminopeptidase transgene is expressed along the length of the gut, and immunolocalisation shows the enzyme in the buccal cavity, pharynx, anterior gut and rectum. It is constitutively expressed as seen by analysis of cDNAs constructed from mRNAs of nematodes taken at 2 h intervals through the life-cycle; and by western blot analysis of protein from the same set of nematodes. Leucine aminopeptidase null mutants had a slower growth rate and delayed onset of egg-laying. We suggest that in C. elegans, leucine aminopeptidase is a digestive enzyme.
为了研究线虫中亮氨酸氨肽酶的功能，通过转染亮氨酸氨肽酶β-半乳糖苷酶报告构建体并对一个无效突变体进行表征，对在基因组序列中鉴定出的秀丽隐杆线虫亮氨酸氨肽酶基因进行了功能分析。亮氨酸氨肽酶转基因沿肠道全长表达，免疫定位显示该酶存在于口腔、咽部、前肠和直肠中。通过对从线虫生命周期中每隔2小时采集的mRNA构建的cDNA进行分析；以及对同一组线虫的蛋白质进行蛋白质印迹分析，发现该基因是组成型表达的。亮氨酸氨肽酶无效突变体的生长速度较慢，产卵起始延迟。我们认为，在秀丽隐杆线虫中，亮氨酸氨肽酶是一种消化酶。
