2006/02/13 by Darin McDonald, Gustavo Carrero, Christi Andrin +2 · 10 citations
Biochemistry, Genetics and Molecular Biology · #Cellular Mechanics and Interactions #Nuclear Structure and Function #Advanced Fluorescence Microscopy Techniques #Nucleoplasm #Biology #Actin remodeling #Actin-binding protein #Actin #Actin remodeling of neurons #MDia1 #Fluorescence recovery after photobleaching #Biophysics #Cytoplasm #Cell biology #Cell nucleus #Interphase #Biochemistry #Actin cytoskeleton #Nucleolus #Cytoskeleton #Cell
paper · pdf · doi:10.1083/jcb.200507101
openalex publication_date 2006/02/13 · openalex created_date 2016/06/24 · openalex updated_date 2026/06/26
Beta-actin, once thought to be an exclusively cytoplasmic protein, is now known to have important functions within the nucleus. Nuclear beta-actin associates with and functions in chromatin remodeling complexes, ribonucleic acid polymerase complexes, and at least some ribonucleoproteins. Proteins involved in regulating actin polymerization are also found in the interphase nucleus. We define the dynamic properties of nuclear actin molecules using fluorescence recovery after photobleaching. Our results indicate that actin and actin-containing complexes are reduced in their mobility through the nucleoplasm diffusing at approximately 0.5 microm2 s(-1). We also observed that approximately 20% of the total nuclear actin pool has properties of polymeric actin that turns over rapidly. This pool could be detected in endogenous nuclear actin by using fluorescent polymeric actin binding proteins and was sensitive to drugs that alter actin polymerization. Our results validate previous reports of polymeric forms of nuclear actin observed in fixed specimens and reveal that these polymeric forms are very dynamic.