Action of a slowly hydrolysable cyclic AMP analogue on developing cells of Dictyostelium discoideum.
Action of a slowly hydrolysable cyclic AMP analogue on developing cells of Dictyostelium discoideum.
复制标题
缓慢水解的环状 AMP 类似物对盘基网柄菌发育细胞的作用。
作者：
C. Rossier;G. Gerisch;D. Malchow
腺苷3 '，5'-环硫代磷酸酯（cAMP-S）是环AMP（cAMP）类似物，其仅被盘基网柄藻的磷酸二酯酶缓慢水解。cAMP-S对细胞表面cAMP受体的亲和力仅比cAMP低一个数量级。cAMP-S可以取代cAMP作为所有受体介导的反应的刺激物，包括趋化性和cAMP脉冲的诱导。cAMP-S不影响D.但在NC-4菌株及其无菌生长衍生物Ax-2的琼脂平板培养物中，其在5 × 10（-7）M的均匀浓度下阻断细胞聚集。另一株野生型D. discoideum，v-12能够在补充有1 mM cAMP-S的琼脂平板上聚集。苍白多软骨藻和紫色多软骨藻的发育也是高度耐cAMP-S的。在Ax-2中，从生长阶段到聚集能力阶段的分化和趋化性都是cAMP-S敏感的，而在V-12中，只有趋化性被抑制。当cAMP-S抑制趋化性时，V-12仍能形成粘连细胞和子实体流。cAMP在10（-3）或10（-4）M的浓度下诱导茎细胞分化，而cAMP-S在10（-6）M的低得多的浓度下在菌株v-12中具有相同的效果。
Adenosine 3',5'-cyclic phosphorothioate (cAMP-S) is a cyclic AMP (cAMP) analogue which is only slowly hydrolysed by phosphodiesterases of Dictyostelium discoideum. The affinity of cAMP-S to cAMP receptors at the cell surface is only one order of magnitude lower than that of cAMP. cAMP-S can replace cAMP as a stimulant with respect to all receptor-mediated responses tested, including chemotaxis and the induction of cAMP pulses. cAMP-S does not affect growth of D. discoideum but it blocks cell aggregation at a uniform concentration of 5 x 10(-7) M in agar plate cultures of strain NC-4 as well as its axenically growing derivative, Ax-2. Another wild-type strain of D. discoideum, v-12, is able to aggregate on agar plates supplemented with 1 mM cAMP-S. The development of Polysphondylium pallidum and P. violaceum is also highly cAMP-S resistant. In Ax-2 both differentiation from the growth phase to the aggregation-competent stage and chemotaxis are cAMP-S sensitive, whereas in v-12 only chemotaxis is inhibited. v-12 can still form streams of cohering cells and fruiting bodies when chemotaxis is inhibited by cAMP-S. Whereas cAMP induces differentiation into stalk cells at concentrations of 10(-3) or 10(-4) M, cAMP-S has the same effect in strain v-12 at the much lower concentration of 10(-6) M.