Rab11-Rab8 cascade dynamics in primary cilia and membrane tubules.

The Rab11-Rab8 cascade mediated by the Rab8 guanine nucleotide exchange factor (GEF), Rabin8, orchestrates multiple membrane transport processes, but Rab membrane loading and exchange dynamics are unclear. Here, we use advanced fluorescence imaging approaches to characterize Rab11, Rab8, and Rabin8 protein dynamics. Using fluorescence ablation and recovery studies (FRAP), we show that Rab8 ciliary trafficking requires Rab11 and Rabin8.

Competitive assembly resolves the stoichiometry of essential proteins in infectious HIV-1 virions.

Unlabelled: During assembly on the plasma membrane, HIV-1 virions incorporate Gag-Pol as well as gp120/gp41 trimers. The Pol region consists of protease, reverse transcriptase and integrase precursors which are essential enzymes required for maturation, reverse transcription, and integration of the viral genome in the next host. gp120/gp41 trimers catalyze the fusion of the virion with its next host.

Baseline findings of a multicentric ambispective cohort study (2021-2022) among hospitalised mucormycosis patients in India.

In India, the incidence of mucormycosis reached high levels during 2021-2022, coinciding with the COVID-19 pandemic. In response to this, we established a multicentric ambispective cohort of patients hospitalised with mucormycosis across India. In this paper, we report their baseline profile, clinical characteristics and outcomes at discharge.

Structure of the HIV immature lattice allows for essential lattice remodeling within budded virions.

For HIV virions to become infectious, the immature lattice of Gag polyproteins attached to the virion membrane must be cleaved. Cleavage cannot initiate without the protease formed by the homo-dimerization of domains linked to Gag. However, only 5% of the Gag polyproteins, termed Gag-Pol, carry this protease domain, and they are embedded within the structured lattice.

Gag-Gag Interactions Are Insufficient to Fully Stabilize and Order the Immature HIV Gag Lattice.

Immature HIV virions harbor a lattice of Gag molecules with significant ordering in CA-NTD, CA-CTD and SP1 regions. This ordering plays a major role during HIV maturation. To test the condition in which the Gag lattice forms in vivo, we assembled virus like particles (VLPs) by expressing only HIV Gag in mammalian cells.

Dynamics of the HIV Gag Lattice Detected by Localization Correlation Analysis and Time-Lapse iPALM.

Immature human immunodeficiency virus (HIV) virions have a lattice of Gag and Gag-Pol proteins anchored to the lumen of their envelope. Using electron microscopy, we demonstrate that HIV virus-like particles (VLPs) assembled by the viral protein Gag and tagged at its C-terminus with the fluorescent protein Dendra2 have the same morphology and size as the VLPs assembled using only HIV Gag. We characterize the photophysical properties of Dendra2 and demonstrate that 60% of Dendra2 molecules can be photoswitched and reliably counted in our interferometric photoactivated localization microscopy (iPALM) setup.

Interferometric fluorescence cross correlation spectroscopy.

Measuring transport properties like diffusion and directional flow is essential for understanding dynamics within heterogeneous systems including living cells and novel materials. Fluorescent molecules traveling within these inhomogeneous environments under the forces of Brownian motion and flow exhibit fluctuations in their concentration, which are directly linked to the transport properties. We present a method utilizing single photon interference and fluorescence correlation spectroscopy (FCS) to simultaneously measure transport of fluorescent molecules within aqueous samples.

Correlative iPALM and SEM resolves virus cavity and Gag lattice defects in HIV virions.

Interferometric Photo-Activation-Localization-Microscopy (iPALM) localizes single fluorescent molecules with 20 nm lateral and 10 nm axial resolution. We present a method utilizing glass coverslip lithography for correlative imaging between iPALM and scanning electron microscopy (SEM). Using iPALM on HIV Gag-Dendra virus-like particles (VLPs) we localized the position of HIV Gag proteins.

Short-term biochemical ill effects of insect growth regulator (IGR) pesticides in Cyphoderus javanus Borner (Collembola: Insecta) as potential biomarkers of soil pollution.

The insect growth regulator (IGR) chemicals are considered as safe alternatives to synthetic organic pesticides, but only scant information are available on their possible impact on non-target and ecologically important soil insect fauna of croplands. Previous studies by the authors showed that recommended agricultural doses of IGRs buprofezin (Applaud 25SC at 250 g a.i.