Gabrielides C, Zrike J, Scott W A
Arch Microbiol. 1983 Feb;134(2):108-13. doi: 10.1007/BF00407941.
The correlation between membrane phospholipid composition and total cyclic AMP levels was investigated by using Neurospora lipid auxotrophs under various supplementation conditions. The lipid composition of the supplemented cultures was determined, and the intracellular and extracellular cyclic AMP levels were measured at various stages of the culture growth. Kinetic parameters and the thermostability of adenylate cyclase and of cyclic AMP-dependent phosphodiesterase were measured under all supplementation conditions. In inositol deficient inl cultures the levels of intracellular cyclic AMP decreased exponentially towards the end of the log phase and thereafter. In chol-l; chol-2 cultures, grown in N-monomethylethanolamine and low choline supplementation, the level of intracellular cyclic AMP decreased as function of decreasing exogenous choline supplement. Rates of cyclic AMP extrusion in all cultures were comparable on dry weight basis, and thus not affected by the mycelial lipid composition. Adenylate cyclase activity and thermostability decreased under those supplementation conditions resulting in reduction of cyclic AMP. Cyclic AMP-dependent phosphodiesterase was insensitive to phospholipid changes. Accordingly, it is suggested that specific perturbations in cellular phospholipid composition affect the membrane-bound adenylate cyclase and hence the cyclic AMP synthesis in vivo.
通过在各种补充条件下使用粗糙脉孢菌脂质营养缺陷型菌株，研究了膜磷脂组成与总环磷酸腺苷（cAMP）水平之间的相关性。测定了补充培养物的脂质组成，并在培养生长的各个阶段测量了细胞内和细胞外的cAMP水平。在所有补充条件下测量了腺苷酸环化酶和环磷酸腺苷依赖性磷酸二酯酶的动力学参数及热稳定性。在肌醇缺陷型inl培养物中，对数期结束后细胞内cAMP水平呈指数下降。在以N-单甲基乙醇胺和低胆碱补充物培养的chol-1；chol-2培养物中，细胞内cAMP水平随外源胆碱补充量的减少而降低。所有培养物中环磷酸腺苷的外排率以干重计相当，因此不受菌丝体脂质组成的影响。在导致环磷酸腺苷减少的那些补充条件下，腺苷酸环化酶活性和热稳定性降低。环磷酸腺苷依赖性磷酸二酯酶对磷脂变化不敏感。因此，提示细胞磷脂组成的特定扰动会影响膜结合的腺苷酸环化酶，从而影响体内环磷酸腺苷的合成。
