RT Journal Article SR Electronic T1 Nuclear pore density controls heterochromatin reorganization during senescence JF bioRxiv FD Cold Spring Harbor Laboratory SP 374033 DO 10.1101/374033 A1 Boumendilrid, Charlene A1 Hari, Priya A1 Olsen, Karl C. F. A1 Acosta, Juan Carlos A1 Bickmore, Wendy A. YR 2018 UL http://biorxiv.org/content/early/2018/07/21/374033.abstract AB Oncogene induced senescence (OIS) is a cell cycle arrest program triggered by oncogenic signalling. An important characteristic of OIS is activation of the senescence associated secretory phenotype (SASP)1 which can reinforce cell cycle arrest, lead to paracrine senescence but also promote tumour progression2–4. Concomitant with cell cycle arrest and the SASP activation, OIS cells undergo a striking nuclear chromatin reorganization, with loss of heterochromatin from the nuclear periphery and the appearance of internal senescence-associated heterochromatin foci (SAHF)5. The mechanisms by which SAHF are formed, and their role in cell cycle arrest and expression of the SASP, remain poorly understood. Here we show that nuclear pore density increases during OIS and is responsible for SAHF formation. In particular, we show that the nucleoporin TPR is required for both SAHF formation and maintenance. The TPR-induced loss of SAHF does not affect cell cycle arrest but completely abrogates the SASP. Our results uncover a previously unknown role of nuclear pores in heterochromatin reorganization in mammalian nuclei and in senescence, which uncouples the cell cycle arrest from the SASP.