Inner membrane hub protein that plays both cAMP-dependent and cAMP-independent roles in twitching motility. Regulates intracellular cyclic AMP (cAMP) levels through the activation of adenylate cyclase CyaB. Plays an essential role in a number of virulence mechanisms including type IV pilus (T4P)-mediated assembly and twitching motility as well as cAMP-dependent virulence gene expression. Mediates also type II secretion (T2S) of lipases and proteases. In addition, mediates the cAMP-independent localization of multiple T4P structural and regulatory components to the cell poles (By similarity). This role in directing proteins to the cell pole is not restricted to type IV component and involves other proteins such as the diguanylate cyclase DgcP (PubMed:32080219). Interacts with FimL (By similarity). Interacts with DgcP (PubMed:32080219). The N-terminal domain binds peptidoglycans through LysM motif. In addition, this motif is required for PilQ stability and multimerization. The cytoplasmic domain contains three discontinuous tetratricopeptide repeat (TPR) motifs involved in protein-protein interactions.