Cryo-electron tomography reveals the packaging pattern of RuBisCOs in Synechococcus β-carboxysome.

Carboxysomes are large self-assembled microcompartments that serve as the central machinery of a CO-concentrating mechanism (CCM). Biogenesis of carboxysome requires the fine organization of thousands of individual proteins; however, the packaging pattern of internal RuBisCOs remains largely unknown. Here we purified the intact β-carboxysomes from Synechococcus elongatus PCC 7942 and identified the protein components by mass spectrometry.

Scaling-up and proteomic analysis reveals photosynthetic and metabolic insights toward prolonged H photoproduction in Chlamydomonas hpm91 mutant lacking proton gradient regulation 5 (PGR5).

Clean and sustainable H production is crucial to a carbon-neutral world. H generation by Chlamydomonas reinhardtii is an attractive approach for solar-H from HO. However, it is currently not large-scalable because of lacking desirable strains with both optimal H productivity and sufficient knowledge of underlying molecular mechanism.

Structure and activity of SLAC1 channels for stomatal signaling in leaves.

Stomata in leaves regulate gas exchange between the plant and its atmosphere. Various environmental stimuli elicit abscisic acid (ABA); ABA leads to phosphoactivation of slow anion channel 1 (SLAC1); SLAC1 activity reduces turgor pressure in aperture-defining guard cells; and stomatal closure ensues. We used electrophysiology for functional characterizations of SLAC1 (SLAC1) and cryoelectron microscopy (cryo-EM) for structural analysis of SLAC1 (SLAC1), at 2.

[Advances of the technologies in large-scale membrane proteome identification].

Membrane proteins play important functions not only as receptors and transporters, but also in many other important intracellular functions such as photosynthetic and respiratory electron transport. Identification of membrane proteins is a necessary step to understand their functions. Membrane proteins are generally highly hydrophobic and difficult to be resolved by aqueous solutions, and large-scale proteomic identification of membrane proteins has been a great technical challenge.

The proteome and phosphoproteome of maize pollen uncovers fertility candidate proteins.

Maize is unique since it is both monoecious and diclinous (separate male and female flowers on the same plant). We investigated the proteome and phosphoproteome of maize pollen containing modified proteins and here we provide a comprehensive pollen proteome and phosphoproteome which contain 100,990 peptides from 6750 proteins and 5292 phosphorylated sites corresponding to 2257 maize phosphoproteins, respectively. Interestingly, among the total 27 overrepresented phosphosite motifs we identified here, 11 were novel motifs, which suggested different modification mechanisms in plants compared to those of animals.

AtPUB19, a U-box E3 ubiquitin ligase, negatively regulates abscisic acid and drought responses in Arabidopsis thaliana.

Ubiquitination is an important protein post-translational modification, which is involved in various cellular processes in higher plants, and U-box E3 ligases play important roles in diverse functions in eukaryotes. Here, we describe the functions of Arabidopsis thaliana PUB19 (AtPUB19), which we demonstrated in an in vitro assay to encode a U-box type E3 ubiquitin ligase. AtPUB19 was up-regulated by drought, salt, cold, and abscisic acid (ABA).