RNA granules are assemblies of RNA and proteins inside cells that serve multiple roles and functions. Some of the functions they serve in include a variety of organelles such as germ cell P granules, stress granules, and neuronal granules with diverse functions. Intrinsically disordered domains are abundant in the proteins…
RNA granules are assemblies of RNA and proteins inside cells that serve multiple roles and functions. Some of the functions they serve in include a variety of organelles such as germ cell P granules, stress granules, and neuronal granules with diverse functions. Intrinsically disordered domains are abundant in the proteins responsible for RNA granules, and they have been attributed to the formation and degradation of RNA granules through a liquid-liquid phase separation (LLPS) process. LLPS is typically a reversible process where a homogenous fluid de- mixes into two distinct liquid phases. Here, 47 RNA granule proteins with such disordered regions have been surveyed. These proteins have been simulated using coarse-grained molecular simulations to determine size dependence on temperature change. Upper critical solution temperature (UCST) and lower critical solution temperature (LCST) are phase behaviors that can be calculated using the data gathered for scaling and phase behaviors of these proteins. We discovered that less charged amino acid contents are present in RNA granules in comparison to general disordered sequences. This is in line with the observation that charged amino acids are less preferred for the sequence to phase separate at physiological-relevant temperatures. More interestingly, there seems to be an even mix of sequences contributing to both UCST, LCST, and no phase behaviors and the average temperature dependent behaviors of all these proteins have a relatively weak temperature dependence within the temperature range 300 and 325K. The average suggest that these proteins might collectively contribute to RNA granules in a way that adapts to small temperature fluctuations.
This qualitative study sought to investigate the potential reaction between the 3,3',5,5'-tetramethylbenzidine (TMB) radical and LAF-1 RGG, the N-terminus domain of an RNA helicase which functions as a coacervating intrinsically disordered protein. The study was performed by adding horseradish peroxidase to a solution containing TMB and either LAF-1 or tyrosine…
This qualitative study sought to investigate the potential reaction between the 3,3',5,5'-tetramethylbenzidine (TMB) radical and LAF-1 RGG, the N-terminus domain of an RNA helicase which functions as a coacervating intrinsically disordered protein. The study was performed by adding horseradish peroxidase to a solution containing TMB and either LAF-1 or tyrosine in various concentrations, and monitoring the output through UV-Vis spectroscopy. The reacted species was also analyzed via MALDI-TOF mass spectrometry. UV-Vis spectroscopic monitoring showed that in the presence of LAF-1 or tyrosine, the reaction between HRP and TMB occurred more quickly than the control, as well as in the highest concentration of LAF-1, the evolution of a peak at 482 nm. The analysis through MALDI-TOF spectrometry showed the development of a second peak likely due to the reaction between LAF-1 and TMB, as the Δ between the peaks is 229 Da and the size of the TMB species is 240 Da.
