@article {49675,
	title = {Two alternatively spliced isoforms of the Arabidopsis SR45 protein have distinct roles during normal plant development.},
	journal = {Plant Physiol},
	volume = {150},
	year = {2009},
	month = {2009 Jul},
	pages = {1450-8},
	abstract = {<p>The serine-arginine-rich (SR) proteins constitute a conserved family of pre-mRNA splicing factors. In Arabidopsis (Arabidopsis thaliana), they are encoded by 19 genes, most of which are themselves alternatively spliced. In the case of SR45, the use of alternative 3{\textquoteright} splice sites 21 nucleotides apart generates two alternatively spliced isoforms. Isoform 1 (SR45.1) has an insertion relative to isoform 2 (SR45.2) that replaces a single arginine with eight amino acids (TSPQRKTG). The biological implications of SR45 alternative splicing have been unclear. A previously described loss-of-function mutant affecting both isoforms, sr45-1, shows several developmental defects, including defects in petal development and root growth. We found that the SR45 promoter is highly active in regions with actively growing and dividing cells. We also tested the ability of each SR45 isoform to complement the sr45-1 mutant by overexpression of isoform-specific green fluorescent protein (GFP) fusion proteins. As expected, transgenic plants overexpressing either isoform displayed both nuclear speckles and GFP fluorescence throughout the nucleoplasm. We found that SR45.1-GFP complements the flower petal phenotype, but not the root growth phenotype. Conversely, SR45.2-GFP complements root growth but not floral morphology. Mutation of a predicted phosphorylation site within the alternatively spliced segment, SR45.1-S219A-GFP, does not affect complementation. However, a double mutation affecting both serine-219 and the adjacent threonine-218 (SR45.1-T218A + S219A-GFP) behaves like isoform 2, complementing the root but not the floral phenotype. In conclusion, our study provides evidence that the two alternatively spliced isoforms of SR45 have distinct biological functions.</p>},
	keywords = {Alternative Splicing, Amino Acid Sequence, Arabidopsis, Arabidopsis Proteins, Carrier Proteins, Flowers, Molecular Sequence Data, Mutation, Plant Roots, Protein Isoforms, Ribonucleoproteins, RNA-Binding Proteins, sequence alignment},
	issn = {0032-0889},
	doi = {10.1104/pp.109.138180},
	author = {Zhang, Xiao-Ning and Mount, Stephen M}
}
@article {38302,
	title = {Genome sequence of Silicibacter pomeroyi reveals adaptations to the marine environment},
	journal = {NatureNature},
	volume = {432},
	year = {2004},
	note = {http://www.ncbi.nlm.nih.gov/pubmed/15602564?dopt=Abstract},
	type = {10.1038/nature03170},
	abstract = {Since the recognition of prokaryotes as essential components of the oceanic food web, bacterioplankton have been acknowledged as catalysts of most major biogeochemical processes in the sea. Studying heterotrophic bacterioplankton has been challenging, however, as most major clades have never been cultured or have only been grown to low densities in sea water. Here we describe the genome sequence of Silicibacter pomeroyi, a member of the marine Roseobacter clade (Fig. 1), the relatives of which comprise approximately 10-20\% of coastal and oceanic mixed-layer bacterioplankton. This first genome sequence from any major heterotrophic clade consists of a chromosome (4,109,442 base pairs) and megaplasmid (491,611 base pairs). Genome analysis indicates that this organism relies upon a lithoheterotrophic strategy that uses inorganic compounds (carbon monoxide and sulphide) to supplement heterotrophy. Silicibacter pomeroyi also has genes advantageous for associations with plankton and suspended particles, including genes for uptake of algal-derived compounds, use of metabolites from reducing microzones, rapid growth and cell-density-dependent regulation. This bacterium has a physiology distinct from that of marine oligotrophs, adding a new strategy to the recognized repertoire for coping with a nutrient-poor ocean.},
	keywords = {Adaptation, Physiological, Carrier Proteins, Genes, Bacterial, Genome, Bacterial, marine biology, Molecular Sequence Data, Oceans and Seas, Phylogeny, plankton, RNA, Ribosomal, 16S, Roseobacter, Seawater},
	author = {Moran, Mary Ann and Buchan, Alison and Gonz{\'a}lez, Jos{\'e} M. and Heidelberg, John F. and Whitman, William B. and Kiene, Ronald P. and Henriksen, James R. and King, Gary M. and Belas, Robert and Fuqua, Clay and Brinkac, Lauren and Lewis, Matt and Johri, Shivani and Weaver, Bruce and Pai, Grace and Eisen, Jonathan A. and Rahe, Elisha and Sheldon, Wade M. and Ye, Wenying and Miller, Todd R. and Carlton, Jane and Rasko, David A. and Paulsen, Ian T. and Ren, Qinghu and Daugherty, Sean C. and DeBoy, Robert T. and Dodson, Robert J. and Durkin, A. Scott and Madupu, Ramana and Nelson, William C. and Sullivan, Steven A. and Rosovitz, M. J. and Haft, Daniel H. and J. Selengut and Ward, Naomi}
}
@article {49709,
	title = {Sequence similarity.},
	journal = {Nature},
	volume = {325},
	year = {1987},
	month = {1987 Feb 5-11},
	pages = {487},
	keywords = {Adenosine Triphosphate, Amino Acid Sequence, Animals, Bacterial Proteins, Biological Transport, Active, Carrier Proteins, Drosophila melanogaster, genes, HUMANS, Pigments, Biological, Sequence Homology, Nucleic Acid},
	issn = {0028-0836},
	doi = {10.1038/325487c0},
	author = {Mount, S M}
}
