bims-nucpor 2022-07-10 papers

Issue of 2022–07–10
five papers selected by
Sara Mingu, Johannes Gutenberg University

APL Bioeng. 2022 Jun;6(2): 020901

Understanding the role of mechanics in nucleocytoplasmic transport.

Ion Andreu, Ignasi Granero-Moya, Sergi Garcia-Manyes, Pere Roca-Cusachs.

Cell nuclei are submitted to mechanical forces, which in turn affect nuclear and cell functions. Recent evidence shows that a crucial mechanically regulated nuclear function is nucleocytoplasmic transport, mediated by nuclear pore complexes (NPCs). Mechanical regulation occurs at two levels: first, by force application to the nucleus, which increases NPC permeability likely through NPC stretch. Second, by the mechanical properties of the transported proteins themselves, as mechanically labile proteins translocate through NPCs faster than mechanically stiff ones. In this perspective, we discuss this evidence and the associated mechanisms by which mechanics can regulate the nucleo-cytoplasmic partitioning of proteins. Finally, we analyze how mechanical regulation of nucleocytoplasmic transport can provide a systematic approach to the study of mechanobiology and open new avenues both in fundamental and applied research.

DOI: https://doi.org/10.1063/5.0076034

Methods Mol Biol. 2022 ;2533 99-126

Eukaryotic Ribosome assembly and Nucleocytoplasmic Transport.

Michaela Oborská-Oplová, Ute Fischer, Martin Altvater, Vikram Govind Panse.

The process of eukaryotic ribosome assembly stretches across the nucleolus, the nucleoplasm and the cytoplasm, and therefore relies on efficient nucleocytoplasmic transport. In yeast, the import machinery delivers ~140,000 ribosomal proteins every minute to the nucleus for ribosome assembly. At the same time, the export machinery facilitates translocation of ~2000 pre-ribosomal particles every minute through ~200 nuclear pore complexes (NPC) into the cytoplasm. Eukaryotic ribosome assembly also requires >200 conserved assembly factors, which transiently associate with pre-ribosomal particles. Their site(s) of action on maturing pre-ribosomes are beginning to be elucidated. In this chapter, we outline protocols that enable rapid biochemical isolation of pre-ribosomal particles for single particle cryo-electron microscopy (cryo-EM) and in vitro reconstitution of nuclear transport processes. We discuss cell-biological and genetic approaches to investigate how the ribosome assembly and the nucleocytoplasmic transport machineries collaborate to produce functional ribosomes.

Keywords: Budding Yeast; Nuclear Export; Nuclear Import; Ribosome Assembly; preribosome structure

DOI: https://doi.org/10.1007/978-1-0716-2501-9_7

New Phytol. 2022 Jul 06.

NLR we there yet? Nucleocytoplasmic coordination of NLR-mediated immunity.

Daniel Lüdke, Qiqi Yan, Philipp F W Rohmann, Marcel Wiermer.

Plant intracellular nucleotide-binding leucine-rich repeat immune receptors (NLRs) perceive the activity of pathogen-secreted effector molecules that, when undetected, promote colonization of hosts. Signaling from activated NLRs converges with and potentiates downstream responses from activated pattern recognition receptors (PRRs) that sense microbial signatures at the cell surface. Efficient signaling of both receptor branches relies on the host cell nucleus as an integration point for transcriptional reprogramming, and on the macromolecular transport processes that mediate the communication between cytoplasm and nucleoplasm. Studies on nuclear pore complexes (NPCs), the nucleoporin proteins (NUPs) that compose NPCs, and nuclear transport machinery constituents that control nucleocytoplasmic transport, have revealed that they play important roles in regulating plant immune responses. Here, we discuss the contributions of nucleoporins and nuclear transport receptor (NTR)-mediated signal transduction in plant immunity with an emphasis on NLR immune signaling across the nuclear compartment boundary and within the nucleus. We also highlight and discuss cytoplasmic and nuclear functions of NLRs and their signaling partners and further consider potential implications of NLR activation and resistosome formation in both cellular compartments for mediating plant pathogen resistance and programmed host cell death.

Keywords: NLR immune receptor; Nuclear pore complex (NPC); nuclear envelope (NE); nuclear transport receptor (NTR); nucleocytoplasmic NLR signaling; plant immunity

DOI: https://doi.org/10.1111/nph.18359

BMC Plant Biol. 2022 Jul 04. 22(1): 317

MdNup62 interactions with MdHSFs involved in flowering and heat-stress tolerance in apple.

Chenguang Zhang, Na An, Peng Jia, Wei Zhang, Jiayan Liang, Hua Zhou, Dong Zhang, Juanjuan Ma, Caiping Zhao, Mingyu Han, Xiaolin Ren, Libo Xing.

Because of global warming, the apple flowering period is occurring significantly earlier, increasing the probability and degree of freezing injury. Moreover, extreme hot weather has also seriously affected the development of apple industry. Nuclear pore complexes (NPCs) are main channels controlling nucleocytoplasmic transport, but their roles in regulating plant development and stress responses are still unknown. Here, we analysed the components of the apple NPC and found that MdNup62 interacts with MdNup54, forming the central NPC channel. MdNup62 was localized to the nuclear pore, and its expression was significantly up-regulated in 'Nagafu No. 2' tissue-cultured seedlings subjected to heat treatments. To determine MdNup62's function, we obtained MdNup62-overexpressed (OE) Arabidopsis and tomato lines that showed significantly reduced high-temperature resistance. Additionally, OE-MdNup62 Arabidopsis lines showed significantly earlier flowering compared with wild-type. Furthermore, we identified 62 putative MdNup62-interacting proteins and confirmed MdNup62 interactions with multiple MdHSFs. The OE-MdHSFA1d and OE-MdHSFA9b Arabidopsis lines also showed significantly earlier flowering phenotypes than wild-type, but had enhanced high-temperature resistance levels. Thus, MdNUP62 interacts with multiple MdHSFs during nucleocytoplasmic transport to regulate flowering and heat resistance in apple. The data provide a new theoretical reference for managing the impact of global warming on the apple industry.

Keywords: Apple; Flowering; Heat stress; MdHSFs; MdNup62; Nuclear pore complex

DOI: https://doi.org/10.1186/s12870-022-03698-3

Regen Ther. 2022 Dec;21 87-95

NUP160 knockdown inhibits the progression of diabetic nephropathy in vitro and in vivo.

Jiayong Xie, Zhi Chen, Gang Yao, Ying Yuan, Wenjuan Yu, Qiang Zhu.

Diabetic nephropathy (DN) is a severe diabetic complication and podocyte damage is a hallmark of DN. The Nucleoporin 160 (NUP160) gene was demonstrated to regulate cell proliferation and apoptosis in mouse podocytes. This study explored the possible role and mechanisms of NUP160 in high glucose-triggered podocyte injury. A rat model of DN was established by intraperitoneal injection of 60 mg/kg streptozotocin (STZ). Podocytes were treated with 33 mM high glucose. The effects of the Nup160 on DN and its mechanisms were assessed using MTT, flow cytometry, Western blot, ELISA, RT-qPCR, and luciferase reporter assays. The in vivo effects of NUP160 were analyzed by HE, PAS, and MASSON staining assays. The NUP160 level was significantly upregulated in podocytes treated with 33 mM high glucose. Functionally, NUP160 knockdown alleviated high glucose-induced apoptosis and inflammation in podocytes. Mechanistically, miR-495-3p directly targeted NUP160, and lncRNA HCG18 upregulated NUP160 by sponging miR-495-3p by acting as a ceRNA. Additionally, NUP160 overexpression reversed the effects of HCG18 knockdown in high glucose treated-podocytes. The in vivo assays indicated that NUP160 knockdown alleviated the symptoms of DN rats. NUP160 knockdown plays a key role in preventing the progression of DN, suggesting that targeting NUP160 may be a potential therapeutic strategy for DN treatment.

Keywords: DN, diabetic nephropathy; Diabetic nephropathy; ECM, extracellular matrix; ELISA, Enzyme-linked immunosorbent assay; HCG18; HE, Hematoxylin-eosin; NPC, nuclear pore complex; NUP160; NUP160, Nucleoporin 160; Podocytes; STZ, streptozotocin; ceRNAs, competitive endogenous RNAs; miRNAs, MicroRNAs

DOI: https://doi.org/10.1016/j.reth.2022.05.011