A CHEMOATTRACTANT RECEPTOR CONTROLS DEVELOPMENT IN DICTYOSTELIUM-DISCOIDEUM
A CHEMOATTRACTANT RECEPTOR CONTROLS DEVELOPMENT IN DICTYOSTELIUM-DISCOIDEUM
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DOI：
10.1126/science.3047871
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发表时间：
1988-09-16
期刊：
影响因子：
56.9
通讯作者：
DEVREOTES, PN
中科院分区：
文献类型：
--
作者：
KLEIN, PS;SUN, TJ;DEVREOTES, PN
在其发育的早期阶段，盘基网柄藻表达细胞表面环磷酸腺苷（cAMP）受体。已经表明，这些受体协调单个细胞聚集成多细胞生物体，并调节大量发育调控基因的表达。通过用特异性抗血清筛选，现已从λ gt-11文库中克隆了环AMP受体的互补DNA（cDNA）。编码受体的2-羟色胺酶信使RNA（mRNA）在生长的细胞中是检测不到的，在发育3到4小时时达到最大值，然后下降。当与细胞mRNA杂交时，体外转录的互补RNA特异性地阻止受体多肽的体外翻译。当cDNA在网骨藻细胞中表达时，未分化的细胞特异性结合环AMP。用表达互补mRNA（反义）的载体转化的细胞系不表达环AMP受体蛋白。这些细胞在饥饿期间未能进入发育的聚集阶段，而对照和野生型细胞在24小时内聚集并完成发育程序。反义转化体的表型表明，环AMP受体是必不可少的发展。推导的受体的氨基酸序列揭示了高百分比的疏水残基分组在七个域，类似于视紫红质和其他受体被认为与G蛋白相互作用。它与牛视紫红质共享氨基酸序列同一性并具有免疫交叉反应性。提出了一个模型，其中环AMP受体穿过双层7次，富含丝氨酸的胞质羧基末端，配体诱导的受体磷酸化的propsoed网站。
During the early stages of its developmental program, Dictyostelium discoideum expresses cell surface cyclic adenosine monophosphate (cyclic AMP) receptors. It has been suggested that these receptors coordinate the aggregation of individual cells into a multicellular organism and regulate the expression of a large number of developmentally regulated genes. The complementary DNA (cDNA) for the cyclic AMP receptor has now been cloned from .lambda.gt-11 libraries by screening with specific antiserum. The 2-kilobase messenger RNA (mRNA) that encodes the receptor is undetectable in growing cells, rises to a maximum at 3 to 4 hours of development, and then declines. In vitro transcribed complementary RNA, when hybridized to cellular mRNA, specifically arrests in vitro translation of the receptor polypeptide. When the cDNA is expressed in Dictyostelium cells, the undifferentiated cells specifically bind cyclic AMP. Cell lines transformed with a vector that expresses complementary mRNA (antisense) do not express the cyclic AMP receptor protein. These cells fail to enter the aggregation stage of development during starvation, whereas control and wild-type cells aggregate and complete the developmental program within 24 hours. The phenotype of the antisense transformants suggests that the cyclic AMP receptor is essential for development. The deduced amino acid sequence of the receptor reveals a high percentage of hydrophobic residues grouped in seven domains, similar to the rhodopsins and other receptors believed to interact with G proteins. It shares amino acid sequence identity and is immunologically cross-reactive with bovine rhodopsin. A model is proposed in which the cyclic AMP receptor crosses the bilayer seven times with a serine-rich cytoplasmic carboxyl terminus, the propsoed site of ligand-induced receptor phosphorylation.