Heyl A, Muth J, Santandrea G, O'Connell T, Serna A, Thompson R D
MPI für Züchtungsforschung, Köln, Germany.
Mol Genet Genomics. 2001 Oct;266(2):180-9. doi: 10.1007/s004380100561.
A cDNA clone has been obtained for a low-abundance, seed-specific mRNA that encodes a polypeptide which defines a novel family of plant proteins with some similarities to the DnaJ class of molecular chaperones. The MEM1 (Maize Endosperm Motif binding protein) protein is capable of binding to the endosperm motif and activating transcription in the yeast one-hybrid system. Recombinant MEM1 was shown to bind in vitro to nucleic acids, with a preference for RNA over DNA. MEM1 is capable of forming homodimers, a property that is dependent on a domain close to the C-terminus of the protein. The protein is expressed in mid- to late-term endosperm cells. Subcellular fractionation and size fractionation under non-denaturing conditions indicate that the protein is present in the cytosol of endosperm cells. Possible roles of MEM1 in endosperm and protein body development are discussed.
已获得一个低丰度、种子特异性mRNA的cDNA克隆，该mRNA编码一种多肽，该多肽定义了一个新的植物蛋白家族，与分子伴侣的DnaJ类有一些相似之处。MEM1（玉米胚乳基序结合蛋白）蛋白能够结合胚乳基序并在酵母单杂交系统中激活转录。重组MEM1在体外显示出与核酸结合，对RNA的偏好超过DNA。MEM1能够形成同源二聚体，这一特性取决于靠近蛋白质C末端的结构域。该蛋白在胚乳细胞发育的中期到后期表达。非变性条件下的亚细胞分级分离和大小分级分离表明该蛋白存在于胚乳细胞的细胞质中。讨论了MEM1在胚乳和蛋白体发育中的可能作用。
