Rubino S, Mann S K, Hori R T, Pinko C, Firtel R A
Department of Biology, University of California, San Diego, La Jolla 92093.
Dev Biol. 1989 Jan;131(1):27-36. doi: 10.1016/s0012-1606(89)80035-1.
We have previously shown that the developmentally regulated gene D2 is induced during aggregation by pulses of cAMP, which act via the cell surface receptor and consequent signal transduction pathways (W. Rowekamp and R.A. Firtel, 1980, Dev. Biol. 79, 409-418; S.K.O. Mann and R.A. Firtel, 1987, Mol. Cell. Biol. 7, 458-469; S.K.O. Mann, C. Pinko, and R.A. Firtel, 1988, Dev. Biol., in press). In this manuscript, we compare the complete derived amino acid sequence for D2 to two cloned and sequenced eukaryotic esterases and examine the requirement of the D2 gene product for development. Amino acid sequence data comparisons suggest that D2 encodes a serine esterase with strong sequence identity to Torpedo acetylcholine esterase and a Drosophila esterase. The protein has a putative leader sequence, suggesting that it is shunted into vesicles. Using an antisense gene construct driven by a Discoidin I promoter, whose transcriptional activity depends on the growth conditions of the cells, we show that inhibition of D2 mRNA accumulation results in an abnormal developmental program that includes the absence of normal streaming and incomplete aggregate formation and subsequent development. We suggest that D2 encodes an esterase function required for proper aggregation and subsequent development.
我们先前已经表明，发育调控基因D2在聚集过程中由cAMP脉冲诱导产生，cAMP通过细胞表面受体及后续的信号转导途径发挥作用（W. 罗韦坎普和R.A. 菲特尔，1980年，《发育生物学》79卷，409 - 418页；S.K.O. 曼和R.A. 菲特尔，1987年，《分子细胞生物学》7卷，458 - 469页；S.K.O. 曼、C. 平科和R.A. 菲特尔，1988年，《发育生物学》，待发表）。在本论文中，我们将D2完整的推导氨基酸序列与两种已克隆并测序的真核酯酶进行比较，并研究D2基因产物对发育的需求。氨基酸序列数据比较表明，D2编码一种丝氨酸酯酶，与电鳐乙酰胆碱酯酶和一种果蝇酯酶具有很强的序列同一性。该蛋白质有一个推定的前导序列，表明它被转运到小泡中。使用由盘状蛋白I启动子驱动的反义基因构建体，其转录活性取决于细胞的生长条件，我们发现抑制D2 mRNA的积累会导致异常的发育程序，包括正常的细胞质流动缺失、聚集体形成不完全以及后续发育异常。我们认为D2编码一种正常聚集和后续发育所需的酯酶功能。
