Ramakrishna N, Smedman M, Gillam B
NYS Institute for Basic Research in Developmental Disabilities, Staten Island 10314, USA.
Arch Biochem Biophys. 1996 Feb 15;326(2):243-51. doi: 10.1006/abbi.1996.0072.
To establish a cell line expressing enhanced levels of beta-amyloid precursor protein (beta-APP), we constructed plasmid DNAs expressing beta-APP-751 mRNA and transfected them into COS-1 cells. Using a modified version of the reverse transcriptase polymerase chain reaction which is RNA sensitive to study the beta-APP iso-RNAs, we have made the unexpected observation that enhanced expression of beta-APP-751 mRNA resulted in a significant reduction of beta-APP-770 and -695 mRNA levels. Suppression of beta-APP-770 and -695 was also observed in cells expressing truncated and chimeric beta-App-751 mRNAs. Similar observations were made in P19 cells expressing a chimeric beta-APP-751 mRNA where endogenous beta-APP-751 mRNA levels also were decreased. Also, suppression of beta-APP-770 and -751 mRNAs was observed in human kidney cells expressing exogenous beta-APP-695 mRNA.
为建立一个表达增强水平β-淀粉样前体蛋白（β-APP）的细胞系，我们构建了表达β-APP-751 mRNA的质粒DNA，并将其转染到COS-1细胞中。使用对RNA敏感的逆转录聚合酶链反应的改良版本来研究β-APP同工RNA，我们意外地观察到β-APP-751 mRNA的增强表达导致β-APP-770和-695 mRNA水平显著降低。在表达截短和嵌合β-App-751 mRNA的细胞中也观察到β-APP-770和-695的抑制。在表达嵌合β-APP-751 mRNA且内源性β-APP-751 mRNA水平也降低的P19细胞中也有类似观察结果。此外，在表达外源性β-APP-695 mRNA的人肾细胞中观察到β-APP-770和-751 mRNA的抑制。
