André B, Noegel A A, Schleicher M
Adolf-Butenandt-Institut/Zellbiologie, München, Germany.
FEBS Lett. 1996 Mar 11;382(1-2):198-202. doi: 10.1016/0014-5793(96)00176-7.
A full-length genomic DNA fragment that codes for a novel EF-hand protein Dictyostelium discoideum was cloned and sequenced. The protein is composed of 168 amino acids and contains four consensus sequences that are typical for (Ca2+)-binding EF-hand domains. The protein sequence exhibits only minor similarities to other calmodulin-type proteins from Dictyostelium. The genomic DNA harbors two short introns; their positions suggest that the gene is unrelated to the EF-hand proteins from the calmodulin group. Northern blot analysis showed that the mRNA level was significantly increased during development. Polyclonal antibodies raised against the recombinant protein recognized in Western blots a protein of about 20 kDa. Like the mRNA, also the protein was more abundant in developing cells. Overlay experiments with 45Ca2+ indicated that the EF-hands in fact have (Ca2+)-binding activity. The recent description of CBP1, another calmodulin-type Dictyostelium protein that is upregulated during development [Coukell et al. (1995) FEBS Lett. 362, 342-346], suggests that D. discoideum contains a family of EF-hand proteins that have specific functions during distinct steps of development. We therefore designate the protein described in this report as CBP2.
克隆并测序了编码新型EF-手型蛋白盘基网柄菌（Dictyostelium discoideum）的全长基因组DNA片段。该蛋白由168个氨基酸组成，包含四个典型的（Ca2+）结合EF-手型结构域的共有序列。该蛋白序列与盘基网柄菌的其他钙调蛋白型蛋白仅有微小的相似性。基因组DNA含有两个短内含子；它们的位置表明该基因与钙调蛋白组的EF-手型蛋白无关。Northern印迹分析表明，在发育过程中mRNA水平显著增加。针对重组蛋白产生的多克隆抗体在Western印迹中识别出一种约20 kDa的蛋白。与mRNA一样，该蛋白在发育中的细胞中也更为丰富。用45Ca2+进行的覆盖实验表明，EF-手型结构域实际上具有（Ca2+）结合活性。最近对CBP1的描述，CBP1是另一种在发育过程中上调的盘基网柄菌钙调蛋白型蛋白[库凯尔等人（1995年），《欧洲生物化学学会联合会快报》362卷，342 - 346页]，表明盘基网柄菌含有一个EF-手型蛋白家族，它们在发育的不同阶段具有特定功能。因此，我们将本报告中描述的蛋白命名为CBP2。
