Rentier-Delrue F, Swennen D, Prunet P, Lion M, Martial J A
Laboratoire Central de Génie Génétique, Université de Liège, Belgium.
DNA. 1989 May;8(4):261-70. doi: 10.1089/dna.1.1989.8.261.
We have isolated cDNA clones encoding tilapia prolactin (tiPRL) from a cDNA library prepared from tilapia (Oreochromis niloticus) anterior pituitary glands. A trout PRL cDNA fragment was used as hybridization probe to select the recombinant plasmids carrying the tiPRL coding sequence. Two types of PRL cDNA were isolated and their complete nucleotide sequence determined. The larger cDNA (tiPRL-I) codes for a polypeptide of 212 amino acids, including a putative signal sequence of 24 amino acids, and contains a 3' untranslated region of 787 bp. The second prolactin cDNA (tiPRL-II) encodes a polypeptide of 200 amino acids, including a presumptive signal peptide of 23 amino acids, and contains a noncoding region of 512 bp. tiPRL-I and tiPRL-II cDNA sequences are 81% similar, whereas the encoded proteins share 69% amino acid identity at optimal alignment. Mature tiPRL-I was efficiently expressed in Escherichia coli carrying a plasmid in which the tiPRL-I cDNA was under the control of the phi 10 promoter of T7 bacteriophage. The new recombinant protein representing about 45% of the total cellular proteins was found in inclusion bodies and cross-reacted with salmon PRL antiserum.
我们从尼罗罗非鱼（Oreochromis niloticus）垂体前叶制备的cDNA文库中分离出了编码罗非鱼催乳素（tiPRL）的cDNA克隆。用虹鳟鱼PRL cDNA片段作为杂交探针，筛选携带tiPRL编码序列的重组质粒。分离出两种类型的PRL cDNA，并测定了它们的完整核苷酸序列。较大的cDNA（tiPRL-I）编码一个由212个氨基酸组成的多肽，包括一个由24个氨基酸组成的推定信号序列，并含有一个787 bp的3'非翻译区。第二个催乳素cDNA（tiPRL-II）编码一个由200个氨基酸组成的多肽，包括一个由23个氨基酸组成的推定信号肽，并含有一个512 bp的非编码区。tiPRL-I和tiPRL-II cDNA序列的相似性为81%，而在最佳比对时，所编码的蛋白质的氨基酸同一性为69%。成熟的tiPRL-I在携带一种质粒的大肠杆菌中高效表达，该质粒中tiPRL-I cDNA受T7噬菌体的phi 10启动子控制。在包涵体中发现了占总细胞蛋白约45%的新重组蛋白，并且该重组蛋白能与鲑鱼PRL抗血清发生交叉反应。
