Da Silva Alejandro J, Hästbacka Hendrik S E, Puustinen Mikael C, Pessa Jenny C, Luoto Jens C, Sundström Erika, Goult Benjamin T, Jacquemet Guillaume, Henriksson Eva, Sistonen Lea
Faculty of Science and Engineering, Cell Biology, Åbo Akademi University, 20520 Turku, Finland.
Turku Bioscience Centre, University of Turku and Åbo Akademi University, 20520 Turku, Finland.
iScience. 2025 Jan 4;28(2):111745. doi: 10.1016/j.isci.2025.111745. eCollection 2025 Feb 21.
Talin-1 (TLN1) is best known to activate integrin receptors and transmit mechanical stimuli to the actin cytoskeleton at focal adhesions. However, the localization of TLN1 is not restricted to focal adhesions. By utilizing both subcellular fractionations and confocal microscopy analyses, we show that TLN1 localizes to the nucleus in several human cell lines, where it is tightly associated with the chromatin. Importantly, small interfering RNA (siRNA)-mediated depletion of endogenous TLN1 triggers extensive changes in the gene expression profile of human breast epithelial cells. To determine the functional impact of nuclear TLN1, we expressed a TLN1 fusion protein containing a nuclear localization signal. Our findings revealed that the accumulation of nuclear TLN1 alters the expression of a subset of genes and impairs the formation of cell-cell clusters. This study introduces an additional perspective on the canonical view of TLN1 subcellular localization and function.
踝蛋白-1(TLN1)最为人所知的是激活整合素受体,并在粘着斑处将机械刺激传递至肌动蛋白细胞骨架。然而,TLN1的定位并不局限于粘着斑。通过亚细胞分级分离和共聚焦显微镜分析,我们发现TLN1在几种人类细胞系中定位于细胞核,在细胞核中它与染色质紧密相关。重要的是,小干扰RNA(siRNA)介导的内源性TLN1缺失会引发人类乳腺上皮细胞基因表达谱的广泛变化。为了确定细胞核TLN1的功能影响,我们表达了一种含有核定位信号的TLN1融合蛋白。我们的研究结果表明,细胞核TLN1的积累会改变一部分基因的表达,并损害细胞-细胞簇的形成。本研究为TLN1亚细胞定位和功能的传统观点引入了一个新的视角。