Elborough K M, Swinhoe R, Winz R, Kroon J T, Farnsworth L, Fawcett T, Martinez-Rivas J M, Slabas A R
Biological Sciences Department, University of Durham, U.K.
Biochem J. 1994 Jul 15;301 ( Pt 2)(Pt 2):599-605. doi: 10.1042/bj3010599.
One independent and two overlapping rape cDNA clones have been isolated from a rape embryo library. We have shown that they encode a 2.3 kb and a 2.5 kb stretch of the full-length acetyl-CoA carboxylase (ACCase) cDNA, corresponding to the biotin-binding and transcarboxylase domains respectively. Using the cDNA in Northern-blot analysis we have shown that the mRNA for ACCase has a higher level of expression in rape seed than in rape leaf and has a full length of 7.5 kb. The level of expression during rape embryogenesis was compared with both oil deposition and expression of two fatty acid synthetase components enoyl-(acyl-carrier-protein) reductase and 3-oxoacyl-(acyl-carrier-protein) reductase. Levels of ACCase mRNA were shown to peak at 29 days after anthesis during embryonic development, similarly to enoyl-(acyl-carrier-protein) reductase and 3-oxoacyl-(acyl-carrier-protein) reductase mRNA. In addition, a full-length genomic clone (19 kb) of Arabidopsis ACCase has been isolated and partially sequenced. Analysis of the clone has allowed the first plant ACCase activity domains (biotin carboxylase-biotin binding-transcarboxylase) to be ordered and assigned. Southern-blot analysis using the Arabidopsis clone indicates that ACCase is a single-copy gene in Arabidopsis but is encoded by a small gene family in rape.
从油菜胚文库中分离出了一个独立的和两个重叠的油菜cDNA克隆。我们已经表明，它们分别编码全长乙酰辅酶A羧化酶（ACCase）cDNA的2.3 kb和2.5 kb片段，分别对应生物素结合结构域和转羧酶结构域。利用该cDNA进行Northern杂交分析，我们发现ACCase的mRNA在油菜种子中的表达水平高于油菜叶片，全长为7.5 kb。将油菜胚胎发生过程中的表达水平与油的积累以及两种脂肪酸合成酶成分烯酰-（酰基载体蛋白）还原酶和3-氧代酰基-（酰基载体蛋白）还原酶的表达进行了比较。结果表明，ACCase mRNA水平在胚胎发育的开花后29天达到峰值，与烯酰-（酰基载体蛋白）还原酶和3-氧代酰基-（酰基载体蛋白）还原酶mRNA相似。此外，还分离出了拟南芥ACCase的一个全长基因组克隆（19 kb）并进行了部分测序。对该克隆的分析使得首次对植物ACCase活性结构域（生物素羧化酶-生物素结合-转羧酶）进行了排序和定位。使用拟南芥克隆进行的Southern杂交分析表明，ACCase在拟南芥中是单拷贝基因，但在油菜中由一个小基因家族编码。
