Peterson M L, Perry R P
Proc Natl Acad Sci U S A. 1986 Dec;83(23):8883-7. doi: 10.1073/pnas.83.23.8883.
mRNAs encoding the membrane-associated (mu m) and secreted (mu s) forms of mu heavy chain are derived from transcripts of the same immunoglobulin gene by differential RNA processing. To help elucidate the mechanism that regulates the production of these two mu mRNAs during the course of B-lymphoid maturation, we produced a series of specifically modified mu-chain genes and studied their expression when transfected into cells representing either early or late developmental stages. We have established that proper regulation depends on linkage of the mu s and mu m poly(A) addition sites and the length of the mu s-mu m intron. Deletion of an 800 to 900-nucleotide segment from the central region of this intron abolishes regulation; replacement of this segment with miscellaneous DNA sequences restores it. From these results we propose a model in which regulation is principally achieved by competition between cleavage/polyadenylylation of the mu s site and splicing of the C mu 4 and mu m exons.
编码膜相关（μm）和分泌型（μs）μ重链形式的mRNA，是通过不同的RNA加工过程，从同一个免疫球蛋白基因的转录本衍生而来的。为了帮助阐明在B淋巴细胞成熟过程中调节这两种μmRNA产生的机制，我们构建了一系列经过特定修饰的μ链基因，并研究了将它们转染到代表早期或晚期发育阶段的细胞时的表达情况。我们已经确定，适当的调节取决于μs和μm聚腺苷酸化位点的连接以及μm-μs内含子的长度。从该内含子的中心区域缺失800至900个核苷酸片段会消除调节作用；用其他DNA序列替换该片段可恢复调节作用。根据这些结果，我们提出了一个模型，其中调节主要是通过μs位点的切割/聚腺苷酸化与Cμ4和μm外显子的剪接之间的竞争来实现的。
