α-Actinin 1 and α-actinin 4: Contrasting roles in the survival, motility, and RhoA signaling of astrocytoma cells
α-Actinin is a prominent actin filament associated protein for which different isoforms exist. Here, we have examined whether the two highly homologous non-muscle α-actinin isoforms 1 and 4 exhibit functional differences in astrocytoma cells. The protein levels of these isoforms were differentially regulated during the development and progression of astrocytomas, as α-actinin 1 was higher in astrocytomas compared to normal brains whereas α-actinin 4 was elevated in high-grade astrocytomas compared to normal brains and low grade astrocytomas. RNAi demonstrated contrasted contributions of α-actinin 1 and 4 to the malignant behavior of U-373, U-87 and A172 astrocytoma cells. While α-actinin 1 appeared to favor the expansion of U-373, U-87 and A172 astrocytoma cell populations, α-actinin 4 played this role only for U-373 cells. On the other hand, downregulation of α-actinin 4, but not 1, reduced cell motility, adhesion, cortical actin, and RhoA levels. Finally, in the three astrocytoma cell lines examined, α-actinin 1 and 4 had contrasted biochemical properties as α-actinin 4 was significantly more abundant in the actin cytoskeleton than α-actinin 1. Collectively, these findings suggest that α-actinin 1 and 4 are differentially regulated during the development and progression of astrocytomas because each of these isoforms uniquely contributes to distinct malignant properties of astrocytoma cells. © 2010.
Experimental Cell Research
Quick, Q., & Skalli, O. (2010). α-Actinin 1 and α-actinin 4: Contrasting roles in the survival, motility, and RhoA signaling of astrocytoma cells. Experimental Cell Research, 316 (7), 1137-1147. https://doi.org/10.1016/j.yexcr.2010.02.011