Tracking the virus-like particles of Macrobrachium rosenbergii nodavirus in insect cells

Macrobrachium rosenbergii nodavirus (MrNv) poses a major threat to the prawn industry. Currently, no effective vaccine and treatment are available to prevent the spread of MrNv. Its infection mechanism and localisation in a host cell are also not well characterised. The MrNv capsid protein (MrNvc) produced in Escherichia coli self-assembled into virus-like particles (VLPs) resembling the native virus. Thus, fluorescein labelled MrNvc VLPs were employed as a model to study the virus entry and localisation in Spodoptera frugiperda, Sf9 cells. Through fluorescence microscopy and sub-cellular fractionation, the MrNvc was shown to enter Sf9 cells, and eventually arrived at the nucleus. The presence of MrNvc within the cytoplasm and nucleus of Sf9 cells was further confirmed by the Z-stack imaging. The presence of ammonium chloride (NH4Cl), genistein, methyl-β-cyclodextrin or chlorpromazine (CPZ) inhibited the entry of MrNvc into Sf9 cells, but cytochalasin D did not inhibit this process. This suggests that the internalisation of MrNvc VLPs is facilitated by caveolae- and clathrin-mediated endocytosis. The whole internalisation process of MrNvc VLPs into a Sf9 cell was recorded with live cell imaging. We have also identified a potential nuclear localisation signal (NLS) of MrNvc through deletion mutagenesis and verified by classical-NLS mapping. Overall, this study provides an insight into the journey of MrNvc VLPs in insect cells.

INTERNALISASI STANDAR HAM INTERNASIONAL DALAM PENGUJIAN UNDANG-UNDANG OLEH MAHKAMAH KONSTITUSI

The issue to be discussed in this article is the internalisation process of international human rights standards into domestic forum through the judicial review mechanism of the constitutionality of legislation by the MKRI. This article argues that MKRI should consider international human rights standards in reviewing the constitutionality of legislation based on Ch. XA of the UUD NRI 1945. The argument based on the prescription that the international human rights standard are binding on States and requiring them to conform their laws and their offcial behavior to the international norm.IntisariTulisan ini membahas isu proses internalisasi standar HAM internasional dalam forum domestik melalui mekanisme pengujian konstitusionalitas undang-undang oleh MKRI. Tulisan ini berargumen bahwa MKRI seyogianya mempertimbangkan standar HAM internasional dalam menguji konstitusionalitas undangundang berdasarkan Bab XA UUD NRI 1945. Argumen itu didasarkan pada preskripsi bahwa standar HAM internasional berlaku/mengikat kepada negara dan mensyaratkannya untuk menyesuaikan undangundang beserta tindakan pejabatnya dengan kaidah HAM internasional tersebut