Okladnova O, Syagailo Y V, Tranitz M, Riederer P, Stöber G, Mössner R, Lesch K P
Clinical Neurochemistry, Department of Psychiatry, University of Würzburg, Füchsleinstrasse 15, Würzburg, 97080, Germany.
Genomics. 1999 Apr 1;57(1):110-9. doi: 10.1006/geno.1998.5711.
Spatiotemporal expression of the PAX3 gene is tightly regulated during development. We have isolated and sequenced the 5'-flanking regulatory region of human PAX3. Primer extension and ribonuclease protection mapping revealed that transcription is initiated from a single start site downstream of a TATA-like motif in human brain and peripheral tissues. Functional dissection of the gene's 5'-flanking region, which had been fused to a luciferase reporter gene and transiently expressed in rhabdomyosarcoma (RD) and cos-7 cells, indicated that the upstream region of PAX3 contains multiple positive and negative cis-acting regulatory elements. While the basal promoter is likely to be driven by two CCAAT boxes located at nucleotide positions -90 and -135, a cluster of regulatory elements acting as a strong repressor was detected between nucleotides -1200 and -650. Comparison of human and murine sequences revealed more than 90% identity in this segment. A polymorphic (CA)n repeat sequence and a G/C substitution are located 337 bp and 328 bp upstream of the transcription start site, respectively. PCR-based systematic screening for length variations in 225 unrelated individuals of a Caucasian population showed a bimodal distribution of multiple alleles containing between 13 and 30 repeat units. Although the (CA)25 variant of this PAX3 gene-linked polymorphic region (PAX3LPR) conferred lower transcriptional efficiency on the PAX3 promoter, a regulatory impact of the PAX3LPR on PAX3 expression related to brain plasticity and function remains to be demonstrated.
PAX3基因的时空表达在发育过程中受到严格调控。我们分离并测序了人类PAX3基因的5'侧翼调控区。引物延伸和核糖核酸酶保护图谱分析表明，在人类大脑和外周组织中，转录起始于类TATA基序下游的单个起始位点。将该基因的5'侧翼区与荧光素酶报告基因融合，并在横纹肌肉瘤（RD）细胞和cos-7细胞中瞬时表达，对其进行功能剖析，结果表明PAX3基因的上游区域包含多个正向和负向顺式作用调控元件。虽然基础启动子可能由位于核苷酸位置-90和-135的两个CCAAT框驱动，但在核苷酸-1200至-650之间检测到一组作为强抑制子的调控元件。人类和小鼠序列的比较显示，该区域的同一性超过90%。一个多态性（CA）n重复序列和一个G/C替换分别位于转录起始位点上游337 bp和328 bp处。对高加索人群225名无关个体进行基于PCR的长度变异系统筛查，结果显示包含13至30个重复单元的多个等位基因呈双峰分布。虽然该PAX3基因相关多态性区域（PAX3LPR）的（CA）25变体赋予PAX3启动子较低的转录效率，但PAX3LPR对与脑可塑性和功能相关的PAX3表达的调控作用仍有待证实。
