As a proof of concept, we bioengineered the vesicular stomatitis virus glycoprotein (VSV-G)-based near-infrared (NIR) active viral nanoconstructs (NAVNs) encapsulating indocyanine green dye (ICG) for NIR bioimaging.
NAVNs are spherical in size and have the intrinsic cellular-fusogenic properties of VSV-G. Further, the NIR imaging displaying higher fluorescence intensity in NAVNs treated cells suggests enhanced cellular uptake and delivery of ICG by NAVNs compared to the free form of ICG and for more information than visit joplink recombinant human to highlights. The overall study highlights the effectiveness of VSV-G-based VNPs as an efficient delivery system for NIR fluorescence imaging.
Phosphorylation of Trans-active response DNA binding protein-of 43 kDa promotes its cytoplasmic aggregation and modulates its function in tau mRNA stability and exon 10 alternative splicing
Trans-active response DNA-binding protein of 43 kDa (TDP-43) promotes tau mRNA instability and tau exon 10 inclusion. Aggregation of phosphorylated TDP-43 is associated with amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). CK1ε phosphorylates TDP-43 at multiple sites, enhances its cytoplasmic aggregation and modu-lates its function in tau mRNA processing.
To determine roles of TDP-43 site-specific phos-phorylation in its localization, aggregation, and function in tau mRNA processing, TDP-43 was mutated to alanine or aspartic acid at Ser379, Ser403/404, or Ser409/410 to block or mimic phosphorylation. Site-specific phosphorylation of TDP-43 and its mutants by CK1ε was studied in vitro and in cultured cells. Cytoplasmic and nuclear TDP-43 and phospho-TDP-43 were analyzed by Western blots.
Aggregation of TDP-43 was assessed by immunostaining and level of RIPA-insoluble TDP-43. GFP tailed with tau 3′-UTR and mini-tau gene pCI/SI9-LI10 were used to study tau mRNA stability and alternative splicing of tau exon 10. We found that phospho-blocking mutations of TDP-43 at Ser379, Ser403/404, or Ser409/410 were not effectively phosphorylated by CK1ε.
Compared with TDP-43, higher level of phosphorylated TDP-43 in the cytoplasm was observed. Phospho-mimicking mutations at these sites enhanced cytoplasmic aggregation of TDP-43. GFP expression was not inhibited by phospho-blocking mutants of TDP-43, but tau exon 10 inclusion was further enhanced by phospho-blocking mutations at Ser379 and Ser403/404. Phosphorylation of TDP-43 at Ser379, Ser 403/404 or Ser409/410 primes its phosphorylation by CK1ε, promotes TDP-43 cytoplasmic aggregation and modulates its function in tau mRNA processing in site-specific manner.
Oncogenic mutations Q61L and Q61H confer active form-like structural features to the inactive state (state 1) conformation of H-Ras protein
GTP-bound forms of Ras proteins (Ras•GTP) assume two interconverting conformations, “inactive” state 1 and “active” state 2. Our previous study on the crystal structure of the state 1 conformation of H-Ras in complex with guanosine 5′-(β, γ-imido)triphosphate (GppNHp) indicated that state 1 is stabilized by intramolecular hydrogen-bonding interactions formed by Gln61. Since Ras are constitutively activated by substitution mutations of Gln61, here we determine crystal structures of the state 1 conformation of H-Ras•GppNHp carrying representative mutations Q61L and Q61H to observe the effect of the mutations.
The results show that these mutations alter the mode of hydrogen-bonding interactions of the residue 61 with Switch II residues and induce conformational destabilization of the neighboring regions. In particular, Q61L mutation results in acquirement of state 2-like structural features. Moreover, the mutations are likely to impair an intramolecular structural communication between Switch I and Switch II. Molecular dynamics simulations starting from these structures support the above observations. These findings may give a new insight into the molecular mechanism underlying the aberrant activation of the Gln61 mutants.
Effect of Active Coatings Containing Lippa citriodora Kunth. Essential Oil on Bacterial Diversity and Myofibrillar Proteins Degradation in Refrigerated Large Yellow Croaker
The research evaluated the effects of locust bean gum (LBG) and sodium alginate (SA) active coatings containing 0.15, 0.30 or 0.60% lemon verbena (Lippa citriodora Kunth.) essential oil (LVEO) on the bacterial diversity and myofibrillar proteins (MPs) of large yellow croaker during refrigerated storage at 4 °C for 18 days. Variability in the dominant bacterial community in different samples on the 0, 9th and 18th day was observed.
. Pseudomonas and Shewanella were the two major genera identified during refrigerated storage. At the beginning, the richness of Pseudomonas was about 37.31% and increased for control (CK) samples during refrigerated storage, however, the LVEO-treated samples increased sharply from day 0 to the 9th day and then decreased.
LBG-SA coatings containing LVEO treatments significantly delayed MPs oxidation by retarding the formation of free carbonyl compounds and maintaining higher sulfhydryl content, higher Ca2+-ATPase activity, better organized secondary (higher contents of α-helix and β-sheet) and tertiary structures during refrigerated storage.
The transmission electron microscope (TEM) images showed that the integrity of the sarcomere was damaged; the boundaries of the H-, A-, and I-bands, Z-disk, and M-line were fuzzy in the CK samples at the end of storage. However, the LVEO-treated samples were still regular in appearance with distinct dark A-bands, light I-bands, and Z-disk. In brief, LBG-SA active coatings containing LVEO treatments suggested a feasible method for protecting the MPs of large yellow croaker during refrigerated storage.
Ribosome-Inactivating Proteins of Bougainvillea glabra Uncovered Polymorphism and Active Site Divergence
Ribosome-inactivating proteins (RIPs) are toxic proteins that can inhibit protein synthesis. RIPs purified from Bougainvillea have low nonspecific toxicity, showing promise for processing applications in the agricultural and medical fields. However, systematic research on the polymorphism of Bougainvillea RIPs is lacking, and it is worth exploring whether different isoforms differ in their active characteristics. The transcriptional and translational expression of type I RIPs in Bougainvillea glabra leaves was investigated in this study. Seven RIPs exhibited seasonal variation at both the mRNA and protein levels.
The isoforms BI4 and BI6 showed the highest transcriptional expression in both the summer and autumn samples. Interestingly, BI6 was not detected in the protein level in any of the samples. However, the bioinformatics analysis showed that RIPs derived from the same species were gathered in a different cluster, and that the active sites changed among the isoforms during evolution.
The significant discrepancy in Bougainvillea RIPs mainly locates at both termini of the amino acid sequence, particularly at the C terminus. Post-translational modifications may also exist in Bougainvillea RIPs. It is concluded that the reason for the polymorphism of Bougainvillea RIPs may be that these proteins are encoded by multiple genes due to genetic processes such as gene duplication and mutation. According to the results of sequence analysis, the possible functional differences of B. glabra RIP isoforms are discussed with regard to the observed discrepancy in both active sites and structures.
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