Regulation and secretion of early developmentally controlled enzymes during axenic growth in Dictyostelium discoideum.
Regulation and secretion of early developmentally controlled enzymes during axenic growth in Dictyostelium discoideum.
复制标题
盘基网柄菌无菌生长过程中早期发育控制酶的调节和分泌。
DOI：
10.1016/0012-1606(81)90409-7
复制
发表时间：
1981
影响因子：
2.7
通讯作者：
Dimond,RL
中科院分区：
文献类型：
--
作者：
Burns,RA;Livi,GP;Dimond,RL
细胞黏菌盘基网柄菌（Dictyosteelium discoideum）中最早发育控制的四种酶在丰富培养基中无菌生长期间积累。我们已经证明，在低细胞滴度下，N-乙酰氨基葡萄糖苷酶、α-甘露糖苷酶、亮氨酸氨肽酶和丙氨酸转氨酶的比活性均处于非常低或营养水平，与以细菌为食物源生长的阿米巴相当。在生长的指数期，所有四种酶都急剧积累，达到至少与发育期间一样高的细胞比活性。这种积累的幅度受生长培养基中的改变的影响。我们认为，这些结果，结合先前的调查，表明，一个受限制的早期发展的一段开始在无菌生长。这意味着生长和早期发育在这种生物体中并不是相互排斥的事件。溶酶体酶的分泌也受生长培养基组成的影响。在所有培养基中，包括在细菌悬浮液中的生长，溶酶体酶以显著量分泌。培养基组成对这些酶分泌的影响和对无菌生长期间发育控制酶的调节的影响是一致的。不受发育调节的溶酶体酶的分泌在这些培养基中受到影响，表明这些酶的调节和分泌受到单独的控制。很明显，研究这种生物体中溶酶体酶的调节必须考虑酶的分泌及其细胞特异性活性，以正确反映基因表达水平。
The four earliest developmentally controlled enzymes in the cellular slime mold,Dictyostelium discoideum, accumulate during axenic growth in rich media. We have shown that at low cell titers the specific activities ofN-acetylglucosaminidase, α-mannosidase, leucine aminopeptidase, and alanine transaminase are each at very low or vegetative levels comparable to amoebae which have been grown on bacteria as the food source. During the exponential phase of growth all four enzymes accumulate dramatically reaching cellular specific activities at least as high as during development. The magnitude of this accumulation is influenced by alterations in the growth medium. We suggest that these results, combined with those of prior investigations, indicate that a restricted segment of early development is initiated during axenic growth. This means that growth and early development are not mutually exclusive events in this organism. The secretion of lysosomal enzymes is also affected by the composition of the growth media. In all media, including growth in bacterial suspensions, lysosomal enzymes are secreted in significant quantities. There is a correspondence in the effects of media composition on the secretion of these enzymes and on the regulation of developmentally controlled enzymes during axenic growth. The secretion of lysosomal enzymes that are not developmentally regulated is affected in these media, suggesting that the regulation and secretion of these enzymes are under separate control. It is clear that studies of the regulation of lysosomal enzymes in this organism must take into account the secretion of the enzymes as well as their cellular specific activities to properly reflect levels of gene expression.