Like other retroviruses, human immunodeficiency virus type 1 (HIV-1) selectively packages genomic RNA (gRNA) during virus assembly. However, in the absence of the gRNA, cellular messenger RNAs (mRNAs) are packaged. While the gRNA is selected because of its cis-acting packaging signal, the mechanism of this selection is not understood. The affinity of Gag (the viral structural protein) for cellular RNAs at physiological ionic strength is not much higher than that for the gRNA. However, binding to the gRNA is more salt-resistant, implying that it has a higher non-electrostatic component. We have previously studied the spacer 1 (SP1) region of Gag and showed that it can undergo a concentration-dependent conformational transition. We proposed that this transition represents the first step in assembly, i.e., the conversion of Gag to an assembly-ready state. To explain selective packaging of gRNA, we suggest here that binding of Gag to gRNA, with its high non-electrostatic component, triggers this conversion more readily than binding to other RNAs; thus we predict that a Gag–gRNA complex will nucleate particle assembly more efficiently than other Gag–RNA complexes. New data shows that among cellular mRNAs, those with long 3′-untranslated regions (UTR) are selectively packaged. It seems plausible that the 3′-UTR, a stretch of RNA not occupied by ribosomes, offers a favorable binding site for Gag.
from #AlexandrosSfakianakis via Alexandros G.Sfakianakis on Inoreader http://ift.tt/2cxE0Lb
via IFTTT
Εγγραφή σε:
Σχόλια ανάρτησης (Atom)
Δημοφιλείς αναρτήσεις
-
Publication date: Available online 4 January 2018 Source: European Journal of Radiology Author(s): Peiyao Zhang, Jing Wang, Qin Xu, Zhen...
-
Abstract Objective Valid measurement systems recording tooth mobility upon displacement within the subtle range of physiological strains...
-
Consulting to Finance: How to Network, Tell Your Story, Spin Your Resume, and Dominate Your Investment Banking and Private Equity Interviews...
-
Abstract Purpose Pedicle screw malplacement, leading to neurological symptoms, vascular injury, and premature implant loosening, is not ...
-
MRI Characteristics of Primary Tumors and Metastatic Lesions in Molecular Subgroups of Pediatric Medulloblastoma: A Single-Center ...
-
Chromatin-based mechanisms offer therapeutic targets in acute myeloid leukemia (AML) that are of great current interest. In this study, we c...
-
A comparison of the academic performance and intelligence scores of asthmatic and nonasthmatic primary... A comparison of the academic perfo...
-
The Importance of Flexion MRI in Hirayama Disease with Special Reference to Laminodural Space Measurements. AJNR Am J Neuroradio...
Δεν υπάρχουν σχόλια:
Δημοσίευση σχολίου