scholarly journals Organelle evolution, fragmented rRNAs, and Carl

RNA Biology ◽  
2014 ◽  
Vol 11 (3) ◽  
pp. 213-216 ◽  
Author(s):  
Michael W Gray
Keyword(s):  
Author(s):  
Duckhyun Lhee ◽  
JunMo Lee ◽  
Khaoula Ettahi ◽  
Chung Hyun Cho ◽  
Ji-San Ha ◽  
...  

Abstract Eukaryotic photosynthetic organelles, plastids, are the powerhouses of many aquatic and terrestrial ecosystems. The canonical plastid in algae and plants originated >1 billion years ago and therefore offers limited insights into the initial stages of organelle evolution. To address this issue, we focus here on the photosynthetic amoeba Paulinella micropora strain KR01 (hereafter, KR01) that underwent a more recent (ca. 124 Mya) primary endosymbiosis, resulting in a photosynthetic organelle termed the chromatophore. Analysis of genomic and transcriptomic data resulted in a high-quality draft assembly of size 707 Mbp and 32,361 predicted gene models. A total of 291 chromatophore targeted proteins were predicted in silico, 206 of which comprise the ancestral organelle proteome in photosynthetic Paulinella species with functions, among others, in nucleotide metabolism and oxidative stress response. Gene co-expression analysis identified networks containing known high light stress response genes as well as a variety of genes of unknown function (“dark” genes). We characterized diurnally rhythmic genes in this species and found that over 51% are dark. It was recently hypothesized that large double-stranded DNA viruses may have driven gene transfer to the nucleus in Paulinella and facilitated endosymbiosis. Our analyses do not support this idea, but rather suggest that these viruses in the KR01 and closely related P. micropora MYN1 genomes resulted from a more recent invasion.


2008 ◽  
Vol 18 (8) ◽  
pp. R345-R347 ◽  
Author(s):  
Patrick J. Keeling ◽  
John M. Archibald
Keyword(s):  

2020 ◽  
Vol 151 ◽  
pp. 106903 ◽  
Author(s):  
Deise J.P. Gonçalves ◽  
Robert K. Jansen ◽  
Tracey A. Ruhlman ◽  
Jennifer R. Mandel
Keyword(s):  

2015 ◽  
Vol 14 (12) ◽  
pp. 1264-1275 ◽  
Author(s):  
Petr Rada ◽  
Abhijith Radhakrishna Makki ◽  
Verena Zimorski ◽  
Sriram Garg ◽  
Vladimír Hampl ◽  
...  

ABSTRACT Mitochondrial evolution entailed the origin of protein import machinery that allows nuclear-encoded proteins to be targeted to the organelle, as well as the origin of cleavable N-terminal targeting sequences (NTS) that allow efficient sorting and import of matrix proteins. In hydrogenosomes and mitosomes, reduced forms of mitochondria with reduced proteomes, NTS-independent targeting of matrix proteins is known. Here, we studied the cellular localization of two glycolytic enzymes in the anaerobic pathogen Trichomonas vaginalis : PP i -dependent phosphofructokinase ( Tv PP i -PFK), which is the main glycolytic PFK activity of the protist, and ATP-dependent PFK ( Tv ATP-PFK), the function of which is less clear. Tv PP i -PFK was detected predominantly in the cytosol, as expected, while all four Tv ATP-PFK paralogues were imported into T. vaginalis hydrogenosomes, although none of them possesses an NTS. The heterologous expression of Tv ATP-PFK in Saccharomyces cerevisiae revealed an intrinsic capability of the protein to be recognized and imported into yeast mitochondria, whereas yeast ATP-PFK resides in the cytosol. Tv ATP-PFK consists of only a catalytic domain, similarly to “short” bacterial enzymes, while Sc ATP-PFK includes an N-terminal extension, a catalytic domain, and a C-terminal regulatory domain. Expression of the catalytic domain of Sc ATP-PFK and short Escherichia coli ATP-PFK in T. vaginalis resulted in their partial delivery to hydrogenosomes. These results indicate that Tv ATP-PFK and the homologous ATP-PFKs possess internal structural targeting information that is recognized by the hydrogenosomal import machinery. From an evolutionary perspective, the predisposition of ancient ATP-PFK to be recognized and imported into hydrogenosomes might be a relict from the early phases of organelle evolution.


Science ◽  
2014 ◽  
Vol 346 (6209) ◽  
pp. 532-533 ◽  
Author(s):  
E. Pennisi
Keyword(s):  

2012 ◽  
Vol 22 (9) ◽  
pp. R304-R306 ◽  
Author(s):  
Andrzej Bodył ◽  
Paweł Mackiewicz ◽  
Przemysław Gagat
Keyword(s):  

2002 ◽  
Vol 7 (4) ◽  
pp. 175-182 ◽  
Author(s):  
William Zerges
Keyword(s):  

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