Related Experiment Video

Updated: Oct 10, 2025

Visualization of HIV-1 Gag Binding to Giant Unilamellar Vesicle GUV Membranes
08:21

Visualization of HIV-1 Gag Binding to Giant Unilamellar Vesicle GUV Membranes

Published on: July 28, 2016

9.1K

Molecular Determinants in tRNA D-arm Required for Inhibition of HIV-1 Gag Membrane Binding

Christopher Sumner1, Osamu Kotani2, Shuohui Liu3

  • 1Dept. of Microbiology and Immunology, University of Michigan, Ann Arbor, MI, United States.

Journal of Molecular Biology
|December 9, 2021
PubMed

Plasma-membrane-specific localization of Gag, an essential step in HIV-1 particle assembly, is regulated by the interaction of the Gag MA domain with PI(4,5)P2 and tRNA-mediated inhibition of non-specific or premature membrane binding. Different tRNAs inhibit PI(4,5)P2-independent membrane binding to varying degrees in vitro; however, the structural determinants for this difference remain unknown. Here we demonstrate that membrane binding of full-length Gag synthesized in vitro using reticulocyte lysates is inhibited when RNAs that contain the anticodon arm of tRNAPro, but not that of tRNALys3, are added exogenously. In contrast, in the context of a liposome binding assay in which the effects of tRNAs on purified MA were tested, full-length tRNALys3 showed greater inhibition of MA membrane binding than full-length tRNAPro. While transplantation of the D loop sequence of tRNALys3 into tRNAPro resulted in a modest increase in the inhibitory effect relative to WT tRNAPro, replacing the entire D arm sequence with that of tRNALys3 was necessary to confer the full inhibitory effects upon tRNAPro. Together, these results demonstrate that the D arm of tRNALys3 is a major determinant of strong inhibition of MA membrane binding and that this inhibitory effect requires not only the D loop, which was recently reported to contact the MA highly basic region, but the loop sequence in the context of the D arm structure.

Keywords:
acidic phospholipidhighly basic regionlipid-protein interactiontRNA–protein interactionvirus assembly

More Related Videos

Nucleocapsid Annealing-Mediated Electrophoresis NAME Assay Allows the Rapid Identification of HIV-1 Nucleocapsid Inhibitors08:33

Nucleocapsid Annealing-Mediated Electrophoresis NAME Assay Allows the Rapid Identification of HIV-1 Nucleocapsid Inhibitors

Published on: January 19, 2015

9.0K
Conformational Evaluation of HIV-1 Trimeric Envelope Glycoproteins Using a Cell-based ELISA Assay07:10

Conformational Evaluation of HIV-1 Trimeric Envelope Glycoproteins Using a Cell-based ELISA Assay

Published on: September 14, 2014

14.5K

Related Concept Videos

Transfer RNA Synthesis02:36

Transfer RNA Synthesis

One of the unique features of tRNA is the presence of modified bases. In some tRNAs, modified bases account for nearly 20% of the total bases in the molecule. Altogether, these unusual bases protect the tRNA from enzymatic degradation by RNases.
Each of these chemical modifications is carried by a specific enzyme, post-transcription. All of these enzymes have unique base and site-specificity. Methylation, the most common chemical modification, is carried by at least nine different enzymes, with...
12.3K
Eukaryotic Transcription Inhibitors01:52

Eukaryotic Transcription Inhibitors

Certain biochemical processes, such as embryonic development and cell growth regulation, depend on the repression of specific genes. DNA binding proteins known as eukaryotic transcription inhibitors regulate the repression of gene expression in eukaryotes. The presence of these inhibitors at the required location and time in the cell is triggered by the presence of hormones and additional signals from other cells.
Eukaryotic transcription inhibitors usually contain two distinct domains, a...
10.1K
Rab Proteins01:14

Rab Proteins

Rab proteins constitute the largest family of monomeric GTPases, of which 70 members are present in humans. Rab proteins and their effectors regulate consecutive stages of vesicle transport such as vesicle transport, docking, and fusion to the correct recipient membrane.
Rab proteins switch between a cytosolic, GDP-bound inactive state and a membrane-anchored, GTP-bound active state. By themselves, Rabs show slow rates of GDP/GTP exchange and GTP hydrolysis. Thus, Rab proteins are considered...
4.3K
Transcription Attenuation in Prokaryotes02:42

Transcription Attenuation in Prokaryotes

Transcriptional attenuation occurs when RNA transcription is prematurely terminated due to the formation of a terminator mRNA hairpin structure.  Bacteria use these hairpins to regulate the transcription process and control the synthesis of several amino acids including histidine, lysine, threonine, and phenylalanine. Transcription attenuation takes place in the non-coding regions of mRNA.
There are several different mechanisms used to attenuate transcription. In ribosome mediated...
16.3K
tRNA Activation02:26

tRNA Activation

Aminoacyl-tRNA synthetases are present in both eukaryotes and bacteria. Though eukaryotes have 20 different aminoacyl-tRNA synthetases to couple to 20 amino acids, many bacteria do not have genes for all of these aminoacyl-tRNA synthetases. Despite this, they still use all 20 amino acids to synthesize their proteins. For instance, some bacteria do not have the gene encoding the enzyme that couples glutamine with its partner tRNA. In these organisms, one enzyme adds glutamic acid to all of the...
20.4K
Leaky Scanning02:28

Leaky Scanning

During most eukaryotic translation processes, the small 40S ribosome subunit scans an mRNA from its 5' end until it encounters the first start AUG codon. The large 60S ribosomal subunit then joins the smaller one to initiate protein synthesis. The location of the translation initiation is largely determined by the nucleotides near the start codon as there may be multiple translation initiation sites present on the mRNA.  Marilyn Kozak discovered that the sequence RCCAUGG (where R...
5.3K