ARHGAP29 is required for keratinocyte proliferation and migration

Abstract

BACKGROUND: RhoA GTPase plays critical roles in actin cytoskeletal remodeling required for controlling a diverse range of cellular functions including cell proliferation, cell adhesions, migration and changes in cell shape. RhoA cycles between an active GTP-bound and an inactive GDP-bound form, a process that is regulated by guanine nucleotide exchange factors (GEFs), and GTPase-activating proteins (GAPs). ARHGAP29 is a GAP expressed in keratinocytes of the skin and is decreased in the absence of Interferon Regulator Factor 6, a critical regulator of cell proliferation and migration. However, the role for ARHGAP29 in keratinocyte biology is unknown. RESULTS: Novel ARHGAP29 knockdown keratinocyte cell lines were generated using both CRISPR/Cas9 and shRNA technologies. Knockdown cells exhibited significant reduction of ARHGAP29 protein (50-80%) and displayed increased filamentous actin (stress fibers), phospho-myosin light chain (contractility), cell area and population doubling time. Furthermore, we found that ARHGAP29 knockdown keratinocytes displayed significant delays in scratch wound closure in both single cell and collective cell migration conditions. Particularly, our results show a reduction in path lengths, speed, directionality and persistence in keratinocytes with reduced ARHGAP29. The delay in scratch closure was rescued by both adding back ARHGAP29 or adding a ROCK inhibitor to ARHGAP29 knockdown cells. CONCLUSIONS: These data demonstrate that ARHGAP29 is required for keratinocyte morphology, proliferation and migration mediated through the RhoA pathway.

IQGAP3 Is an Important Mediator of Skin Inflammatory Diseases

“…They are indispensable for cell spreading and migration, as well as the establishment of epithelial cell-cell contacts, and enhance IQGAP oligomerization [26,27]. Inhibition of GTPase activation leads to significant delays in wound closure [28]. Moreover, the altered growth dynamics and changes in cornification and barrier functions observed in IQGAP3-knockdown cells may be directly influenced by dysregulated GTPase signaling pathways.…”