HIV-1 integrase (IN) is

HIV-1 employs the cellular nuclear import machinery to actively transport its preintegration complex (PIC) into the nucleus for integration of the viral DNA. Several viral karyophilic proteins and cellular import factors have been suggested to contribute to HIV-1 PIC nuclear import and replication. However, how HIV interacts with different cellular machineries to ensure efficient nuclear import of its preintegration complex in dividing and nondividing cells is still not fully understood. In this study, we have investigated different importin ␣ (Imp␣) family members for their impacts on HIV-1 replication, and we demonstrate that short hairpin RNA (shRNA)-mediated Imp␣3 knockdown (KD) significantly impaired HIV infection in HeLa cells, CD4؉ C8166 T cells, and primary macrophages. Moreover, quantitative real-time PCR analysis revealed that Imp␣3-KD resulted in significantly reduced levels of viral 2-long-terminal repeat (2-LTR) circles but had no effect on HIV reverse transcription. All of these data indicate an important role for Imp␣3 in HIV nuclear import. In an attempt to understand how Imp␣3 participates in HIV nuclear import and replication, we first demonstrated that the HIV-1 karyophilic protein integrase (IN) was able to interact with Imp␣3 both in a 293T cell expression system and in HIV-infected CD4 ؉ C8166 T cells. Deletion analysis suggested that a region (amino acids [aa] 250 to 270) in the C-terminal domain of IN is involved in this viral-cellular protein interaction. Overall, this study demonstrates for the first time that Imp␣3 is an HIV integrase-interacting cofactor that is required for efficient HIV-1 nuclear import and replication in both dividing and nondividing cells.HIV-1 replicates productively in nondividing cells, such as monocytes (49,61,74), macrophages (23,37,59,65,71), dendritic cells (47,64), and resting CD4 ϩ T lymphocytes (86), through its ability to undergo active nuclear import by hijacking the host nuclear import machinery. Moreover, active nuclear import is not only required for nondividing-cell infection but also plays a role in the infection of proliferating cells (35). This ability of HIV-1 to enter the nucleus at interphase may contribute significantly to the very high replication rate observed in infected individuals (30,70,73) and is one of the crucial steps in HIV-1 replication, which plays a leading role in the establishment of infection and AIDS pathogenesis.The viral double-stranded DNA (dsDNA), which associates with viral and cellular proteins, forms a high-molecular-mass nucleoprotein complex called the preintegration complex (PIC) in the cytosol of an infected cell (15,51). This large complex has to actively enter the nucleus through the intact nuclear membrane in order to be integrated. At the molecular level, the active nuclear import ability of HIV-1 is attributed to the karyophilic properties of viral PICs. It is known that several viral nucleophilic proteins, including integrase (IN), matrix (MA), and Vpr, are associated with this nucleoprotein complex and pla...

Background: HIV-1 integration is promoted by viral integrase and its cellular cofactors. Results: Nucleoporin 62 interacts with HIV-1 integrase in chromatin, and shRNA knockdown of nucleoporin 62 was able to impair integrase chromatin association and viral replication. Conclusion: Interaction of nucleoporin 62 and HIV-1 integrase contributes to viral DNA integration. Significance: A new nucleoporin was identified as an integrase-binding cofactor required for HIV-1 integration and replication.

In order to better understand the impact of heating temperature on volatiles forming during linoleic acid heating process, volatile profiling was investigated by using thermal‐desorption cryo‐trapping combined with gas chromatography–mass spectrometry. As a result, a total of 42 volatile compounds were detected and identified during this process, including aldehydes (12), ketones (6), alcohols (5), furans (6) acids (10), and aromatic compounds (3). The forming temperature of each volatile was determined. It reveals most volatiles with shorter carbon chains were generated at lower temperatures, while volatiles with longer carbon chains were generated at higher temperatures. Simultaneously, principal component analysis was used to analyze the volatile composition characteristics of linoleic acid at each temperature points. Results show volatile characteristics of linoleic acid had a big difference among different temperatures. One conclusion was drawn the volatile compound formation from linoleic acid is a temperature‐dependent reaction rather than a time‐dependent one during heating. Novelty impact statement Thermal desorption combined with GC–MS could be an effective method for studying the volatile compounds forming mechanism of linoleic acid during heating. Temperature plays a crucial role in the heating process. Volatile compound formation from linoleic acid is a temperature‐dependent reaction rather than a time‐dependent one during heating.

Study design and participants: We performed a retrospective study with laboratory-confirmed COVID-19 patients admitted to Zhongnan Hospital of Wuhan University before March 20, 2020. The diagnosis was confirmed when a positive result was obtained on quantitative real-time reverse-transcriptase polymerase chain reaction (qRT-PCR) from nasal and pharyngeal swab samples. Briefly, the swabs were placed in a virus preservation solution, and the respiratory sample RNA isolation kit (Zhongzhi, Wuhan, China) was used to extract total RNA. The qRT-PCR assay was performed using a SARS coronavirus 2 (SARS-CoV-2) nucleic acid detection kit (Shanghai Bio-Germ Medical Technology Co. Ltd, Shanghai, China). A cycle threshold value (Ctvalue) of < 37 was defined as a positive test result, a Ct value of ≥ 40 indicated a negative test result, and the Ct-value of 37-39 was defined as a suspicious result