Lai J P, Douglas S D, Rappaport E, Wu J M, Ho W Z
Joseph Stokes Jr. Research Institute at the Children's Hospital of Philadelphia, Department of Pediatrics, University of Pennsylvania Medical School, 19104, USA.
J Neuroimmunol. 1998 Nov 2;91(1-2):121-8. doi: 10.1016/s0165-5728(98)00170-2.
We have characterized preprotachykinin (PPT-A) gene transcript splicing products and identified a fourth isoform of PPT-A mRNA transcript in human peripheral blood-isolated monocytes and PBL. Using RT-PCR, Southern blot analysis and nucleotide sequencing analysis, we have identified the four isoforms of PPT-A transcripts (alpha, beta, gamma and delta) in human peripheral blood-isolated monocytes and PBL. The delta-PPT transcript present in the immune cells lacks exons 4 and 6. The sequences of exons 3, 5 and 7 of delta-PPT transcript completely match those of beta-PPT transcript. The alpha-PPT and beta-PPT sequences in these cells are identical to those obtained by Tan and Too (GenBank accession number U37539) and Harmar et al. (Genbank accession number X54469), but differ by a single nucleotide from another entry by Chiwakata et al. (Genbank accession number M68906). In comparison to this latter sequence, there was a C-->T change at amino acid position 87 (CCT-->CTT) which may result in a Pro to Leu change. Identification of the new SP mRNA transcript in both human CNS and immune cells supports the concept of an important biological link between CNS and immune system.
我们已对前速激肽原（PPT-A）基因转录剪接产物进行了表征，并在人外周血分离的单核细胞和外周血淋巴细胞中鉴定出PPT-A mRNA转录本的第四种异构体。通过逆转录聚合酶链反应（RT-PCR）、Southern印迹分析和核苷酸测序分析，我们在人外周血分离的单核细胞和外周血淋巴细胞中鉴定出了PPT-A转录本的四种异构体（α、β、γ和δ）。免疫细胞中存在的δ-PPT转录本缺失外显子4和6。δ-PPT转录本的外显子3、5和7的序列与β-PPT转录本的序列完全匹配。这些细胞中的α-PPT和β-PPT序列与Tan和Too（GenBank登录号U37539）以及Harmar等人（Genbank登录号X54469）获得的序列相同，但与Chiwakata等人（Genbank登录号M68906）的另一个条目相差一个核苷酸。与后一个序列相比，在氨基酸位置87处有一个C→T的变化（CCT→CTT），这可能导致脯氨酸变为亮氨酸。在人中枢神经系统和免疫细胞中均鉴定出这种新的速激肽原（SP）mRNA转录本，这支持了中枢神经系统与免疫系统之间存在重要生物学联系的概念。
