Signal transduction in myxobacteria using eukaryotic protein kinas es and phosphatases.

黄粘球菌btkB基因主要在子实体发育的生长期和早期表达。当在营养培养基中高温（37℃）培养时，btkB突变体的最大细胞密度比野生型降低。磷酸化的BtkA在饥饿诱导后表达较晚，在甘油诱导后表达较早，并且BtkA是成熟孢子形成所必需的。BtkA和BtkB参与胞外多糖的合成。另一方面，Php3表现出pp2c型丝氨酸/苏氨酸蛋白磷酸酶的酶学特性，参与孢子的形成。PhpA与PHP家族具有同源性，可使酪氨酸磷酸化的BtkA和BtkB去磷酸化。这种酶也参与胞外多糖的产生。

Myxococcus xanthus btkB gene is expressed mainly in the growth phase and early stages of fruiting body development. When cultured in nutrient medium at high temperature (37 °C), btkB mutant showed reduced maximum cell density as compared to the wild type. Also, phosphorylated BtkA is expressed late after starvation induction and early after glycerol induction, and BtkA is required for the formation of mature spores.BtkA and BtkB are involved in the synthesis of exopolysaccharide. On the other hand, Php3 showed the enzymatic characteristics of PP2C-type serine/threonine protein phosphatases, and is involved in spore formation. PhpA shares homology with PHP family, and dephosphorylates Tyr-phosphorylated BtkA and BtkB. This enzyme is also involved in the production of exopolysaccharide.