The mechanism for nuclear envelope (NE) assembly is not fully understood. Importin-β and the small GTPase Ran have been implicated in the spatial regulation of NE assembly process. Here we report that chromatin-bound NLS (nuclear localization sequence) proteins provide docking sites for the NE precursor membrane vesicles and nucleoporins via importin-α and -β during NE assembly in Xenopus egg extracts. We show that along with the fast recruitment of the abundant NLS proteins such as nucleoplasmin and histones to the demembranated sperm chromatin in the extracts, importin-α binds the chromatin NLS proteins rapidly. Meanwhile, importin-β binds cytoplasmic NE precursor membrane vesicles and nucleoporins. Through interacting with importin-α on the chromatin NLS proteins, importin-β targets the membrane vesicles and nucleoporins to the chromatin surface. Once encountering Ran-GTP on the chromatin generated by RCC1, importin-β preferentially binds Ran-GTP and releases the membrane vesicles and nucleoporins for NE assembly. NE assembly is disrupted by blocking the interaction between importin-α and NLS proteins with excess soluble NLS proteins or by depletion of importin-β from the extract. Our findings reveal a novel molecular mechanism for NE assembly in Xenopus egg extracts.
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http://dx.doi.org/10.1038/cr.2012.113 | DOI Listing |
Vet Microbiol
January 2025
Shandong Provincial Key Laboratory of Zoonoses, Shandong Agricultural University, Taian, Shandong Province 271018, China; College of Veterinary Medicine, Shandong Agricultural University, Taian, Shandong Province 271018, China. Electronic address:
Mink enteritis virus (MEV) is an important pathogen causing mink viral enteritis. The mechanisms of cell cycle arrest induced by MEV infection and the roles of autophagy in MEV replication remain unclear. In this study, the roles of MEV NS1 protein in inducing cell cycle arrest were investigated, using the in vitro CRFK cell models.
View Article and Find Full Text PDFVet Res
January 2025
Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education, Chengdu, 611130, China.
In herpesvirus, the terminase subunit pUL15 is involved in cleavage of the viral genome concatemers in the nucleus. Previous studies have shown that herpes simplex virus 1 (HSV-1) pUL15 can enter the nucleus without other viral proteins and help other terminase subunits enter the nucleus. However, this study revealed that duck plague virus (DPV) pUL15 cannot localize independently to the nucleus and can only be localized in the nucleus in the presence of pUL28 and pUL33.
View Article and Find Full Text PDFCommun Biol
January 2025
Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA, USA.
Arginine-rich dipeptide repeat proteins (R-DPRs) are highly toxic proteins found in patients with C9orf72-linked amyotrophic lateral sclerosis and frontotemporal dementia (C9-ALS/FTD). R-DPRs can cause toxicity by disrupting the natural phase behavior of RNA-binding proteins (RBPs). Mitigating this abnormal phase behavior is, therefore, crucial to reduce R-DPR-induced toxicity.
View Article and Find Full Text PDFZhongguo Shi Yan Xue Ye Xue Za Zhi
December 2024
Institute of Transfusion Medicine, Blood Center of Zhejiang Province, Hangzhou 310052, Zhejiang Province, China.
Objective: To establish an efficient gene editing method of HLA-I gene to prepare HLA-I universal hematopoietic stem cells.
Methods: The easyedit small guide RNA(sgRNA) was designed according to the sequences of β2 microglobulin gene and synthesized by GenScript company. RNP complexes were formed by NLS-Cas9-NLS nuclease and Easyedit sgRNA according to different molar ratios (1∶1~1∶4).
Osteoarthritis Cartilage
December 2024
Department of Oral Anatomy and Physiology and TMD, College of Stomatology, the Fourth Military Medical University, Xi'an, China; Department of Oral Anatomy and Physiology and TMD, Shanghai Stomatological Hospital & School of Stomatology, Fudan University, Shanghai, China. Electronic address:
Objective: Some cells in temporomandibular joint (TMJ) cartilage undergo proliferation in response to negative pressure, which can be induced in vivo by creating bilateral anterior elevation (BAE). TMJ cartilage harbours CD90-expressing cells, and CD90 expression increases under certain controlled conditions. The parathyroid hormone-related peptide (PTHrP) nuclear localisation segment (NLS) promotes chondrocyte proliferation, and mammalian target of rapamycin (mTOR) signalling plays a regulatory role in promoting PTHrP transcription.
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