biostudies-literatureFan YNCATS NIH HHSNHLBI NIH HHS47-55https://www.ebi.ac.uk/biostudies/studies/S-EPMC3392929biostudies-literatureUnknown198(1)Addition of actin monomer (G-actin) to growing actin filaments (F-actin) at the leading edge generates force for cell locomotion. The polymerization reaction and its regulation have been studied in depth. However, the mechanism responsible for transport of G-actin substrate to the cell front is largely unknown; random diffusion, facilitated transport via myosin II contraction, local synthesis as a result of messenger ribonucleic acid localization, or F-actin turnover all might contribute. By tracking a photoactivatable, nonpolymerizable actin mutant, we show vectorial transport of G-actin in live migrating endothelial cells (ECs). Mass spectrometric analysis identified Myo1c, an unconventional F-actin-binding motor protein, as a major G-actin-interacting protein. The cargo-binding tail domThe Journal of cell biologyMyo1c facilitates G-actin transport to the leading edge of migrating endothelial cells.PMC3392929R01 HL75255P01 HL76491P01 HL029582P01 HL076491UL1 TR000439P01 HL29582R21 HL094841R01 HL075255Hitomi MFan YEswarappa SMFox PLfalseMyo1c facilitates G-actin transport to the leading edge of migrating endothelial cells.Addition of actin monomer (G-actin) to growing actin filaments (F-actin) at the leading edge generates force for cell locomotion. The polymerization reaction and its regulation have been studied in depth. However, the mechanism responsible for transport of G-actin substrate to the cell front is largely unknown; random diffusion, facilitated transport via myosin II contraction, local synthesis as a result of messenger ribonucleic acid localization, or F-actin turnover all might contribute. By tracking a photoactivatable, nonpolymerizable actin mutant, we show vectorial transport of G-actin in live migrating endothelial cells (ECs). Mass spectrometric analysis identified Myo1c, an unconventional F-actin-binding motor protein, as a major G-actin-interacting protein. The cargo-binding tail dom2012-01-01T00:00:00Z2012 Jul2025-05-18T13:06:41.517Z2025-05-18T13:06:41.517ZS-EPMC33929292277827810.1083/jcb.201111088