Leucine Rich Repeat Containing Protein 16A (LRRC16A)

The high-affinity binding between Carmil and CP decreased the affinity of CP for actin barbed ends. Carmil had no effect on actin capping by gelsolin. Mutation analysis confirmed that the central CP-binding domain was necessary and sufficient to inhibit actin capping by CP. Addition of Carmil to rabbit neutrophil extracts increased the rate and extent of Arp2/Arp3 or spectrin -actin seed-induced actin polymerization. Decreasing Carmil levels in human glioblastoma cells by small interfering RNA lowered the F-actin level and slowed cell migration through a mechanism that included decreased lamellipodia protrusion. Wildtype Carmil, but not a Carmil mutant lacking the CP-binding domain, reversed these effects. Overexpression of Carmil in glioblastoma cells increased the fraction of cells with large lamellipodia