1. Classical nuclear localization signals: definition, function, and interaction with importin alpha
Allison Lange, Ryan E Mills, Christopher J Lange, Murray Stewart, Scott E Devine, Anita H Corbett J Biol Chem. 2007 Feb 23;282(8):5101-5. doi: 10.1074/jbc.R600026200. Epub 2006 Dec 14.
The best understood system for the transport of macromolecules between the cytoplasm and the nucleus is the classical nuclear import pathway. In this pathway, a protein containing a classical basic nuclear localization signal (NLS) is imported by a heterodimeric import receptor consisting of the beta-karyopherin importin beta, which mediates interactions with the nuclear pore complex, and the adaptor protein importin alpha, which directly binds the classical NLS. Here we review recent studies that have advanced our understanding of this pathway and also take a bioinformatics approach to analyze the likely prevalence of this system in vivo. Finally, we describe how a predicted NLS within a protein of interest can be confirmed experimentally to be functionally important.
2. Types of nuclear localization signals and mechanisms of protein import into the nucleus
Juane Lu, Tao Wu, Biao Zhang, Suke Liu, Wenjun Song, Jianjun Qiao, Haihua Ruan Cell Commun Signal. 2021 May 22;19(1):60. doi: 10.1186/s12964-021-00741-y.
Nuclear localization signals (NLS) are generally short peptides that act as a signal fragment that mediates the transport of proteins from the cytoplasm into the nucleus. This NLS-dependent protein recognition, a process necessary for cargo proteins to pass the nuclear envelope through the nuclear pore complex, is facilitated by members of the importin superfamily. Here, we summarized the types of NLS, focused on the recently reported related proteins containing nuclear localization signals, and briefly summarized some mechanisms that do not depend on nuclear localization signals into the nucleus. Video Abstract.
3. Nuclear localization signal peptide enhances transfection efficiency and decreases cytotoxicity of poly(agmatine/N,N'-cystamine-bis-acrylamide)/pDNA complexes
Hui Liu, Yanping Sun, Lang Lang, Tianzhi Yang, Xiaoyun Zhao, Cuifang Cai, Zhijun Liu, Pingtian Ding J Cell Biochem. 2019 Oct;120(10):16967-16977. doi: 10.1002/jcb.28958. Epub 2019 May 17.
At present, nonviral gene vectors develop rapidly, especially cationic polymers. A series of bioreducible poly(amide amine) (PAA) polymers containing guanidino groups have been synthesized by our research team. These novel polymer vectors demonstrated significantly higher transfection efficiency and lower cytotoxicity than polyethylenimine (PEI)-25kDa. However, compared with viral gene vectors, relatively low transfection efficiency, and high cytotoxicity are still critical problems confronting these polymers. In this study, poly(agmatine/N,N'-cystamine-bis-acrylamide) p(AGM-CBA) was selected as a model polymer, nuclear localization signal (NLS) peptide PV7 (PKKKRKV) with good biocompatibility and nuclear localization effect was introduced to investigate its impact on transfection efficiency and cytotoxicity. NLS peptide-mediated in vitro transfection was performed in NIH 3T3 cells by directly incorporating NLS peptide with the complexes of p(AGM-CBA)/pDNA. Meanwhile, the transfection efficiency and cytotoxicity of these complexes were evaluated. The results showed that the transfection efficiency could be increased by 5.7 times under the appropriate proportion, and the cytotoxicity brought by the polymer vector could be significantly reduced.
