(A) Enhancement of viral replication by staurosporine. Cells were treated with staurosporine for 2 hours, infected, washed, incubated, and then activated to initiate viral replication. (B) Staurosporine induces cofilin activation in resting T cells. Cells were treated with staurosporine and analyzed by Western blot. (C) Staurosporine induces actin depolymerization in resting T cells. Cells were treated with staurosporine and stained with FITC-phalloidin for flow cytometry. (D) Staurosporine induces cofilin activation by direct inhibition of LIMK1. In vitro LIMK kinase assay was performed in the presence or absence of staurosporine. (E) Model of gp120-CXCR4 signaling in mediating cofilin activation and HIV latent infection. Binding of gp120 to CXCR4 triggers fusion and signal transduction that leads to cofilin activation. Following fusion, the viral preintegration complex is directly anchored onto F-actin to facilitate reverse transcription (Bukrinskaya et al., 1998). Subsequent actin activity mediated by cofilin activation increases cortical actin dynamics and actin treadmilling, which promote the movement of the viral preintegration complex toward the centre of the cell.