Nuclear actin dynamics – From form to function

  title={Nuclear actin dynamics – From form to function},
  author={Maria K. Vartiainen},
  journal={FEBS Letters},

Nuclear functions of actin.

Nuclear actin works in conjunction with different types of actin-binding proteins that regulate actin function and bridge interactions between actin and other nuclear components.

To be or not to be assembled: progressing into nuclear actin filaments

The paradigm states that cytoplasmic actin operates as filaments and nuclear actin is mainly monomeric, acting as a scaffold in transcription complexes, but recent progress forces the field to rethink this issue.

New Insights into Cellular Functions of Nuclear Actin

The recently discovered functions of the nuclear actin pool are discussed, one of the most abundant proteins in eukaryotic cells, which plays a crucial role in shaping the chromatin, genomic, and epigenetic landscape, transcriptional regulation, and DNA repair.

Actin on DNA—An ancient and dynamic relationship

A common feature to the novel modes of actin utilization is the connection between actin and DNA, and here it is aimed to review the recent literature to explore how this connection is exploited in different contexts.

The Potential Roles of Actin in The Nucleus

This historical review is attempt to provide an overview of the current understanding of the functions of actin in the nucleus, such as nuclear matrix association, chromatin remodeling, transcription by RNA polymerases I, II, III and mRNA processing.

A dynamic actin-dependent nucleoskeleton and cell identity.

How nuclear actin, by regulating chromatin structure through phase separation may contribute to the architecture of the nuclear genome during cell differentiation and facilitate the expression of specific gene programs is discussed.

The cytoskeleton and nucleus: the role of actin as a modulator of neuronal gene expression

The impact of actin signalling on nuclear gene expression in the nervous system, where the actin-MRTF-SRF module contributes to various processes including neuronal motility is discussed.

Nuclear Actin Network Assembly by Formins Regulates the SRF Coactivator MAL

It was found that formins polymerized actin inside the mammalian nucleus to drive serum-dependent MAL-SRF activity, which promoted rapid and reversible nuclear actin network assembly, subsequent MAL nuclear accumulation, and SRF activity.

Active maintenance of nuclear actin by importin 9 supports transcription

It is demonstrated that cytoplasmic and nuclear actin pools are dynamically connected and the nuclear import and export mechanisms of actin are identified, which suggest an active transport mechanism in both directions.



Nuclear Actin Regulates Dynamic Subcellular Localization and Activity of the SRF Cofactor MAL

A function of nuclear actin is reported in the regulation of MAL, a coactivator of the transcription factor serum response factor (SRF), and fluorescence resonance energy transfer analysis demonstrates that the MAL-actin interaction responds to extracellular signals.

Nuclear export of actin: a novel mechanism regulating the subcellular localization of a major cytoskeletal protein

It is reported that actin contains two leucine‐rich type nuclear export signal (NES) sequences in the middle part of the molecule, which are both shown to be functional and reveal a novel molecular mechanism controlling the subcellular distribution of actin.

Tracking down the different forms of nuclear actin.

Actin in transcription and transcription regulation.

Dynamic Nuclear Actin Assembly by Arp2/3 Complex and a Baculovirus WASP-Like Protein

A pathogenic mechanism for promoting dynamic actin assembly in the nucleus to enable viral replication and may represent a conserved mode of pathogenesis and reflect viral manipulation of normal functions of nuclear actin.

Regulation of cytoskeletal dynamics by actin-monomer-binding proteins.

Nuclear actin and protein 4.1: Essential interactions during nuclear assembly in vitro

It is reported that structural protein 4.1 and actin colocalize in mammalian cell nuclei using fluorescence microscopy and, by higher-resolution detergent-extracted cell whole-mount electron microscopy, are associated on nuclear filaments.

Nucleoplasmic β-actin exists in a dynamic equilibrium between low-mobility polymeric species and rapidly diffusing populations

This work defines the dynamic properties of nuclear actin molecules using fluorescence recovery after photobleaching and confirms previous reports of polymeric forms ofnuclear actin observed in fixed specimens and reveals that these polymeric form are very dynamic.

Evolution of the gelsolin family of actin‐binding proteins as novel transcriptional coactivators

There is a growing body of evidence supporting a biological role in the nucleus for actin, Arps and actin‐binding proteins and, in particular, the gelsolin family of actin-binding proteins BioEssays 27:388–396, 2005.

Mechanisms underlying intranuclear rod formation.

Transfected muscle and non-muscle cells with mutants of alpha-skeletal actin with live-cell imaging demonstrate that nuclear aggregates of actin form within the nuclear compartment, rather than entering the nucleus after formation in the cytoplasm, and are highly motile and dynamic structures.