Regulation of apical growth and hyphal branching in Streptomyces

► Apical growth in Streptomyces is directed by a polarisome-like complex involving the essential polarity protein DivIVA. ► New branch sites are marked by a 'polarisome-splitting' mechanism. ► DivIVA is subject to phosphorylation by the Ser/Thr kinase AfsK. ► The kinase activity of AfsK is induced when cell wall synthesis at growing tips is blocked. ► The AfsK kinase regulates apical growth and hyphal branching.