Glypican-1 upregulation elicited in response to a cell-impermeable kinase inhibitor and its overexpression enhance HIV infection

We hypothesized that HIV-1, which activates a different scramblase, TMEM16F, to induce PS externalization, may similarly trigger an "outside-in" signaling response to promote viral entry.

To study this process, we utilized a cell-impermeable staurosporine analog, alkyl-CIMSS, which is a broadly active kinase inhibitor that blocks HSV-induced exofacial Akt phosphorylation, and HSV entry. We show that TMEM16F-mediated PS externalization in response to HIV is not associated with Akt translocation; however, surprisingly, pretreatment of cells with alkyl-CIMSS enhanced HIV-1 infection post-entry. To identify potential biological processes that mediated this enhancement, we performed whole-cell total and phosphoproteomics, and bulk RNA sequencing.