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The three mouse actin-depolymerizing factor/cofilins evolved to fulfill cell-type-specific requirements for actin dynamics.

Maria K Vartiainen·Tuija Mustonen·Pieta K Mattila·Pauli J Ojala·Irma Thesleff·Juha Partanen·Pekka Lappalainen
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Abstract

Actin-depolymerizing factor (ADF)/cofilins are essential regulators of actin filament turnover. Several ADF/cofilin isoforms are found in multicellular organisms, but their biological differences have remained unclear. Herein, we show that three ADF/cofilins exist in mouse and most likely in all other mammalian species. Northern blot and in situ hybridization analyses demonstrate that cofilin-1 is expressed in most cell types of embryos and adult mice. Cofilin-2 is expressed in muscle cells and ADF is restricted to epithelia and endothelia. Although the three mouse ADF/cofilins do not show actin isoform specificity, they all depolymerize platelet actin filaments more efficiently than muscle actin. Furthermore, these ADF/cofilins are biochemically different. The epithelial-specific ADF is the most efficient in turning over actin filaments and promotes a stronger pH-dependent actin filament disassembly than the two other isoforms. The muscle-specific cofilin-2 has a weaker actin filament depolymerization activity and displays a 5-10-fold higher affinity for ATP-actin monomers than cofilin-1 and ADF. In steady-state assays, cofilin-2 also promotes filament assembly rather than disassembly. Taken together, these data suggest that the three biochemically distinct mammalian ADF/cofilin isoforms evolved to fulfill specific requirements for actin filament dynamics in different cell types.

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Actin Depolymerizing FactorsActinsAmino Acid SequenceAnimalsCofilin 1Cofilin 2DestrinEndotheliumEpithelial CellsEvolution, MolecularFluorescent Antibody TechniqueHeLa CellsHumansIn Situ HybridizationMaleMiceMicrofilament ProteinsModels, MolecularMolecular Sequence DataMuscle, SkeletalPhylogenyProtein IsoformsProtein Structure, SecondarySequence AlignmentTissue DistributionComparative StudyJournal ArticleResearch Support, Non-U.S. Gov't

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Maria K Vartiainen, Tuija Mustonen, Pieta K Mattila, Pauli J Ojala, Irma Thesleff, Juha Partanen, Pekka Lappalainen. 2002. The three mouse actin-depolymerizing factor/cofilins evolved to fulfill cell-type-specific requirements for actin dynamics.. https://doi.org/10.1091/mbc.01-07-0331

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