J proteins are obligate co-chaperones of Hsp70s. Via their signature J domain, all J proteins interact with their partner Hsp70s and stimulate their weak ATPase activity, which is vital for Hsp70 functions. The dependency of J proteins on their J domain is such that mutations in critical amino acids in the J domain often results into a null phenotype for a particular J protein. Here, we show that the J domain of Djp1, a cytosolic J protein important for peroxisomal protein import in Saccharomyces cerevisiae, is partially dispensable. A complete deletion of Djp1 J domain resulted into only partial loss in peroxisomal protein import function. Instead, the C-terminal domain of Djp1 was found to be essential for proper localization of the peroxisomal targeted GFP-PTS1. Furthermore, we show that Caj1, another cytosolic J protein, also has some role in peroxisomal protein import. Caj1 was found to be partially redundant with Djp1 as cells lacking both Djp1 and Caj1 resulted into a much more severe defect in GFP-PTS1 localization. Based on these results, we propose that dispensability of J domains could be attributed to genetic redundancy between different J proteins sharing common structural topology and cellular localization.

Wide-spectrum solar energy harvesting is of great significance for high-band semiconductors. The present article describes the hydrogen generation from aqueous methanol over a TiO 2 up-conversion (CeF 3 :Ho 3+ ) nanosystem (CHT) under visible light irradiance. In situ CeF 3 :Ho 3+ nanoparticle incorporation into TiO 2 was carried out, and CeF 3 :Ho 3+ nanoparticles (∼4 to 8 nm) were synthesized using a simple polyol reduction method using triethanolamine as a reducing agent. The XRD, UV−Vis, XPS, TEM, BET, and SEM studies reveal the successful formation of a CeF 3 :Ho 3+ -incorporated TiO 2 nanosystem. The enhanced photocatalytic activity of the CeF 3 :Ho 3+ -incorporated TiO 2 nanosystem (CHT) was asserted through the peak hydrogen evolution rate (79.85 μmol h −1 ) under visible light irradiance. Furthermore, the solar-to-hydrogen conversion efficiency (1.37%) and apparent quantum efficiency (4.00%) for the peak rate were calculated and indicated that this could be used as an effective photocatalyst system. The results obtained from wavelength-dependent photocatalytic tests demonstrate that the reaction proceeds through energy absorption from a wide-range wavelength of visible light. For the first time, the in situ incorporation of nano-sized up-conversion material CeF 3 :Ho 3+ into TiO 2 and its utility for efficient sustainable hydrogen generation under visible light irradiance were accomplished with ease.

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In this article, we present the formation of nitrogen (N) doped graphene oxide nanospheres (N-GONs) and investigate their applicability for photocatalytic water splitting. We chose a simple "bottom-up" method for synthesizing N-GONs. Dibenzopyrrole as a basic structural unit was used for constructing N-GONs. Nitration is an intermediate step, subsequent hydrothermal treatment of nitro derivatives imparted oxygen functionalities, which was well proved via CHNS and XPS analysis. ∼ 14 % and 39 % of nitrogen and oxygen were present inside N-GONs. The average size of N-GONs is in-between 30-80 nm. N-GONs typically have a band gap of nearly 2.61 eV. The valance and the conduction bands alignments of N-GONs w.r.t to standard hydrogen electrode were evaluated through UPS and XPS studies. The alignments were found to be well suited for H 2 O splitting applications. N-GONs have n-type semiconductor features and a charge carrier density of 1.12 × 10 22 cm À 3 . While studying photocatalytic dissociation of water we identified oxygen as the only product. Significantly, 1 g of N-GONs produced ∼ 1.3 mmol of oxygen over the course of 1 h. These backgrounds clearly suggest the possibilities of ongoing oxygen reduction and oxygen evolution reactions simultaneously. No-significant traces of H 2 O 2 were observed which suggested immediate H 2 O 2 disproportionation to O 2 and H 2 O on N-GONs. The proposed photocatalytic activity of N-GONs is also confirmed by RRDE method for ORR catalysis.