Zipcode RNA-Binding Proteins and Membrane Trafficking Proteins Cooperate to Transport Glutelin mRNAs in Rice Endosperm.

In rice () endosperm cells, mRNAs encoding glutelin and prolamine are translated on distinct cortical-endoplasmic reticulum (ER) subdomains (the cisternal-ER and protein body-ER), a process that facilitates targeting of their proteins to different endomembrane compartments. Although the - and -factors responsible for mRNA localization have been defined over the years, how these mRNAs are transported to the cortical ER has yet to be resolved. Here, we show that the two interacting glutelin zipcode RNA binding proteins (RBPs), RBP-P and RBP-L, form a quaternary complex with the membrane fusion factors n-ethylmaleimide-sensitive factor (NSF) and the small GTPase Rab5a, enabling mRNA transport on endosomes.

RNA-Binding Protein RBP-P Is Required for Glutelin and Prolamine mRNA Localization in Rice Endosperm Cells.

In developing rice () endosperm, mRNAs of the major storage proteins, glutelin and prolamine, are transported and anchored to distinct subdomains of the cortical endoplasmic reticulum. RNA binding protein RBP-P binds to both glutelin and prolamine mRNAs, suggesting a role in some aspect of their RNA metabolism. Here, we show that rice lines expressing mutant RBP-P mislocalize both glutelin and prolamine mRNAs.

Developmental and Subcellular Organization of Single-Cell C₄ Photosynthesis in Bienertia sinuspersici Determined by Large-Scale Proteomics and cDNA Assembly from 454 DNA Sequencing.

Kranz C4 species strictly depend on separation of primary and secondary carbon fixation reactions in different cell types. In contrast, the single-cell C4 (SCC4) species Bienertia sinuspersici utilizes intracellular compartmentation including two physiologically and biochemically different chloroplast types; however, information on identity, localization, and induction of proteins required for this SCC4 system is currently very limited. In this study, we determined the distribution of photosynthesis-related proteins and the induction of the C4 system during development by label-free proteomics of subcellular fractions and leaves of different developmental stages.

Characterization of RNA binding protein RBP-P reveals a possible role in rice glutelin gene expression and RNA localization.

RNA binding proteins (RBPs) play an important role in mRNA metabolism including synthesis, maturation, transport, localization, and stability. In developing rice seeds, RNAs that code for the major storage proteins are transported to specific domains of the cortical endoplasmic reticulum (ER) by a regulated mechanism requiring RNA cis-localization elements, or zipcodes. Putative trans-acting RBPs that recognize prolamine RNA zipcodes required for restricted localization to protein body-ER have previously been identified.

RiceRBP: A Resource for Experimentally Identified RNA Binding Proteins in Oryza sativa.

RNA binding proteins (RBPs) play an important role not only in nuclear gene expression, but also in cytosolic events, including RNA transport, localization, translation, and stability. Although over 200 RBPs are predicted from the Arabidopsis genome alone, relatively little is known about these proteins in plants as many exhibit no homology to known RBPs in other eukaryotes. Furthermore, RBPs likely have low expression levels making them difficult to identify and study.

RNA targeting to a specific ER sub-domain is required for efficient transport and packaging of α-globulins to the protein storage vacuole in developing rice endosperm.

Studies focusing on the targeting of RNAs that encode rice storage proteins, prolamines and glutelins to specific sub-domains of the endoplasmic reticulum (ER), as well as mis-localization studies of other storage protein RNAs, indicate a close relationship between the ER site of RNA translation and the final site of protein deposition in the endomembrane system in developing rice endosperm. In addition to prolamine and glutelin, rice accumulates smaller amounts of α-globulins, which are deposited together with glutelin in the protein storage vacuole (PSV). In situ RT-PCR analysis revealed that α-globulin RNAs are not distributed to the cisternal ER as expected for a PSV-localized protein, but instead are targeted to the protein body-ER (PB-ER) by a regulated process requiring cis-sorting sequences.

RiceRBP: a database of experimentally identified RNA-binding proteins in Oryza sativa L.

RNA-binding proteins play critical roles at multiple steps during gene expression, including mRNA transport and translation. mRNA transport is particularly important in rice (Oryza sativa L.) in order to ensure the proper localization of the prolamine and glutelin seed storage proteins.

Proteomic analysis of cytoskeleton-associated RNA binding proteins in developing rice seed.

In eukaryotes, RNA binding proteins (RBPs) play an integral role not only in RNA processing within the nucleus, but also in the cytoplasmic events of RNA transport, localization, translation, storage and degradation. While many studies have been done, relatively little is known about RBPs in plants. As part of our continuing efforts to understand cytoplasmic gene expression events in developing rice seed (Oryza sativa L.