Tveten Kristian, Ranheim Trine, Berge Knut Erik, Leren Trond P, Kulseth Mari Ann
Medical Genetics Laboratory, Department of Medical Genetics, Rikshospitalet-Radiumhospitalet Medical Center, N-0027 Oslo, Norway.
Clin Chim Acta. 2006 Nov;373(1-2):151-7. doi: 10.1016/j.cca.2006.05.031. Epub 2006 May 26.
The low density lipoprotein receptor (LDLR) family is a family of structurally related cell surface receptors with conserved exon/intron organization. Several members of this family have been shown to undergo alternative splicing. However, no alternative splicing of the LDLR pre-mRNA has so far been described.
In the present study alternative splicing of human LDLR pre-mRNA has been studied in eight different tissues and four different cell lines using reverse transcription (RT) PCR. A quantitative real-time PCR with exon-exon boundary spanning primers was established to measure the relative amount of two novel isoforms.
Several novel isoforms were identified by RT-PCR of which the isoforms lacking exon 4 or 12 were two of the most prominent. Although highly detectable by RT-PCR, the quantification by real-time PCR revealed low levels of these isoforms.
Novel isoforms of LDLR mRNA are described. Quantification by real-time PCR of two of the alternatively spliced isoforms revealed low amount of these isoforms in the examined tissues and cell lines. Further investigations are needed to evaluate if these isoforms represent functional transcripts of LDLR mRNA.
低密度脂蛋白受体（LDLR）家族是一类结构相关的细胞表面受体家族，具有保守的外显子/内含子结构。该家族的几个成员已被证明会发生可变剪接。然而，迄今为止尚未描述LDLR前体mRNA的可变剪接。
在本研究中，使用逆转录（RT）PCR在八种不同组织和四种不同细胞系中研究了人LDLR前体mRNA的可变剪接。建立了一种跨越外显子-外显子边界引物的定量实时PCR方法，以测量两种新异构体的相对量。
通过RT-PCR鉴定出几种新异构体，其中缺少外显子4或12的异构体是最突出的两种。尽管通过RT-PCR可高度检测到，但实时PCR定量显示这些异构体的水平较低。
描述了LDLR mRNA的新异构体。通过实时PCR对两种可变剪接异构体进行定量分析，结果显示在所检测的组织和细胞系中这些异构体的含量较低。需要进一步研究以评估这些异构体是否代表LDLR mRNA的功能性转录本。
