Staphylococcus aureus produces different secondary cell wall glycopolymers such as wall teichoic acids (WTA) and capsular polysaccharides (CP). These structures play an important role in S. aureus colonization, pathogenesis and bacterial evasion of the host immune defences. To fulfil their diverse functions, biosynthesis of both glycopolymers has to be tightly controlled. Regulation of WTA biosynthesis and modification is only partially understood. The transcription factor MgrA and the two-component systems (TCS) Agr, GraRS, and ArlRS control WTA export, chain-length and modification. CP synthesis is determined by transcriptional and post-transcriptional regulatory circuits. On the transcriptional level expression of the capA-P operon is mainly driven by the alternative Sigma factor B and modulated by several transcriptional factors and TCS. Post-transcriptional mechanisms are in place to avoid conflict between precursor usage by the CP synthesis machinery and the synthesis machinery of other cell wall glycopolymers. The complex interplay of these regulatory systems determines the peculiar, strictly temporal expression of CP in the late growth phase and the high degree of phenotypic heterogeneity. Differential expression of CP, WTA and its modification systems during infection and colonisation are likely important for disease development, immune escape and survival within the host.

金黄色葡萄球菌可产生不同的次级细胞壁糖聚合物，例如壁骨壁酸（WTA）和荚膜多糖（CP）。这些结构在金黄色葡萄球菌定植，发病机理和宿主免疫防御的细菌逃逸中起重要作用。为了实现其多种功能，必须严格控制两种糖聚合物的生物合成。对WTA生物合成和修饰的调节仅部分了解。转录因子MgrA和两组分系统（TCS）Agr，GraRS和ArlRS控制WTA的输出，链长和修饰。CP合成是由转录和转录后调控回路决定的。在capA-P的转录水平表达操纵子主要由替代的Sigma因子B驱动，并由几种转录因子和TCS调节。转录后机制已经到位，以避免CP合成机制与其他细胞壁糖聚合物的合成机制所使用的前体之间发生冲突。这些调控系统的复杂相互作用决定了CP在生长后期的特殊，严格的时间表达以及高度的表型异质性。CP，WTA及其修饰系统在感染和定居过程中的差异表达对于宿主体内疾病的发展，免疫逃逸和生存可能很重要。