Salonen T, Hellsten E, Horelli-Kuitunen N, Peltonen L, Jalanko A
National Public Health Institute and Institute of Biomedicine, Department of Human Molecular Genetics, University of Helsinki, FIN-00300 Helsinki, Finland.
Genome Res. 1998 Jul;8(7):724-30. doi: 10.1101/gr.8.7.724.
Palmitoyl protein thioesterase (PPT) is the defective enzyme in infantile neuronal ceroid lipofuscinosis (INCL), which is a recessively inherited, progressive neurodegenerative disorder. We present here the cloning, chromosomal mapping, genomic structure, and the expression of the cDNA of mouse PPT. The mouse PPT gene spans >21 kb of genomic DNA and contains nine exons with a coding sequence of 918 bp. Fluorescence in situ hybridization to metaphase chromosomes localized the mouse PPT gene to the chromosome 4 conserved syntenic region with human chromosome 1p32 where the human PPT is located. PPT is expressed widely in a variety of mouse tissues. The mouse PPT cDNA is conserved highly with the human and rat PPT both at the nucleotide and amino acid sequence level. Transient expression of mouse PPT in COS-1 cells yielded a 38/36-kD differentially glycosylated polypeptide that was also secreted into culture media. Immunofluorescence analysis of transiently transfected HeLa cells indicated lysosomal localization of mouse PPT. Based on the high conservation of the gene and polypeptide structure as well as similar processing and intracellular localization, the function of PPT in mouse and human are likely to be very similar.
棕榈酰蛋白硫酯酶(PPT)是婴儿神经元蜡样脂褐质沉积症(INCL)中的缺陷酶,INCL是一种隐性遗传的进行性神经退行性疾病。我们在此展示小鼠PPT的克隆、染色体定位、基因组结构及cDNA的表达。小鼠PPT基因跨越超过21kb的基因组DNA,包含9个外显子,编码序列为918bp。对中期染色体进行荧光原位杂交将小鼠PPT基因定位到与人类1p32染色体保守同线区域的4号染色体上,人类PPT基因也位于该区域。PPT在多种小鼠组织中广泛表达。小鼠PPT cDNA在核苷酸和氨基酸序列水平上与人类和大鼠的PPT高度保守。小鼠PPT在COS-1细胞中的瞬时表达产生了一种38/36-kD的差异糖基化多肽,该多肽也分泌到培养基中。对瞬时转染的HeLa细胞进行免疫荧光分析表明小鼠PPT定位于溶酶体。基于基因和多肽结构的高度保守以及相似的加工和细胞内定位,PPT在小鼠和人类中的功能可能非常相似。