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Diversity of Eukaryotic Translational Initiation Factor eIF4E in Protists.

Jagus R, Bachvaroff TR, Joshi B, Place AR - Comp. Funct. Genomics (2012)

Bottom Line: Many more protist sequences are now available from which three clades can be recognized that are distinct from the plant/fungi/metazoan classes.Understanding of the protist eIF4Es will be facilitated as more sequences become available particularly for the under-represented opisthokonts and amoebozoa.Similarly, a better understanding of eIF4Es within each clade will develop as more functional studies of protist eIF4Es are completed.

View Article: PubMed Central - PubMed

Affiliation: Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science, 701 E. Pratt Street, Baltimore, MD 21202, USA.

ABSTRACT
The greatest diversity of eukaryotic species is within the microbial eukaryotes, the protists, with plants and fungi/metazoa representing just two of the estimated seventy five lineages of eukaryotes. Protists are a diverse group characterized by unusual genome features and a wide range of genome sizes from 8.2 Mb in the apicomplexan parasite Babesia bovis to 112,000-220,050 Mb in the dinoflagellate Prorocentrum micans. Protists possess numerous cellular, molecular and biochemical traits not observed in "text-book" model organisms. These features challenge some of the concepts and assumptions about the regulation of gene expression in eukaryotes. Like multicellular eukaryotes, many protists encode multiple eIF4Es, but few functional studies have been undertaken except in parasitic species. An earlier phylogenetic analysis of protist eIF4Es indicated that they cannot be grouped within the three classes that describe eIF4E family members from multicellular organisms. Many more protist sequences are now available from which three clades can be recognized that are distinct from the plant/fungi/metazoan classes. Understanding of the protist eIF4Es will be facilitated as more sequences become available particularly for the under-represented opisthokonts and amoebozoa. Similarly, a better understanding of eIF4Es within each clade will develop as more functional studies of protist eIF4Es are completed.

No MeSH data available.


Cellular organization of Guillardia theta. Former chloroplast genes now inserted in nucleomorph or nuclear chromosomes are indicated in green, and former red algal genes now in the host nucleus are indicated in red. The four endosymbiont membranes are clearly represented.
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fig5: Cellular organization of Guillardia theta. Former chloroplast genes now inserted in nucleomorph or nuclear chromosomes are indicated in green, and former red algal genes now in the host nucleus are indicated in red. The four endosymbiont membranes are clearly represented.

Mentions: Cryptomonads (Chromalveolata/Cryptophyta) are chimeras of two different eukaryotic cells; a flagellate host and a photosynthetic endosymbiont. These organisms are thought to have arisen by secondary symbiogenesis shortly after the origin of the common ancestor of green plants, red, and glaucophyte algae [126–128]. In the cryptomonad Guillardia theta, the flagellate host acquired a chloroplast by engulfing and retaining a red alga. In doing so, the host was able to convert from obligate heterotrophy to an autotrophic way of life [129–131]. In addition to the red algal chloroplast, cryptomonads have retained a vestigial red algal nuclear genome as a minute nucleomorph with three chromosomes [132–134]. The nucleomorph resides in a cell compartment, the periplastid space, that also contains the chloroplast. The cellular organization of Guillardia theta is shown in Figure 5.


Diversity of Eukaryotic Translational Initiation Factor eIF4E in Protists.

Jagus R, Bachvaroff TR, Joshi B, Place AR - Comp. Funct. Genomics (2012)

Cellular organization of Guillardia theta. Former chloroplast genes now inserted in nucleomorph or nuclear chromosomes are indicated in green, and former red algal genes now in the host nucleus are indicated in red. The four endosymbiont membranes are clearly represented.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3388326&req=5

fig5: Cellular organization of Guillardia theta. Former chloroplast genes now inserted in nucleomorph or nuclear chromosomes are indicated in green, and former red algal genes now in the host nucleus are indicated in red. The four endosymbiont membranes are clearly represented.
Mentions: Cryptomonads (Chromalveolata/Cryptophyta) are chimeras of two different eukaryotic cells; a flagellate host and a photosynthetic endosymbiont. These organisms are thought to have arisen by secondary symbiogenesis shortly after the origin of the common ancestor of green plants, red, and glaucophyte algae [126–128]. In the cryptomonad Guillardia theta, the flagellate host acquired a chloroplast by engulfing and retaining a red alga. In doing so, the host was able to convert from obligate heterotrophy to an autotrophic way of life [129–131]. In addition to the red algal chloroplast, cryptomonads have retained a vestigial red algal nuclear genome as a minute nucleomorph with three chromosomes [132–134]. The nucleomorph resides in a cell compartment, the periplastid space, that also contains the chloroplast. The cellular organization of Guillardia theta is shown in Figure 5.

Bottom Line: Many more protist sequences are now available from which three clades can be recognized that are distinct from the plant/fungi/metazoan classes.Understanding of the protist eIF4Es will be facilitated as more sequences become available particularly for the under-represented opisthokonts and amoebozoa.Similarly, a better understanding of eIF4Es within each clade will develop as more functional studies of protist eIF4Es are completed.

View Article: PubMed Central - PubMed

Affiliation: Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science, 701 E. Pratt Street, Baltimore, MD 21202, USA.

ABSTRACT
The greatest diversity of eukaryotic species is within the microbial eukaryotes, the protists, with plants and fungi/metazoa representing just two of the estimated seventy five lineages of eukaryotes. Protists are a diverse group characterized by unusual genome features and a wide range of genome sizes from 8.2 Mb in the apicomplexan parasite Babesia bovis to 112,000-220,050 Mb in the dinoflagellate Prorocentrum micans. Protists possess numerous cellular, molecular and biochemical traits not observed in "text-book" model organisms. These features challenge some of the concepts and assumptions about the regulation of gene expression in eukaryotes. Like multicellular eukaryotes, many protists encode multiple eIF4Es, but few functional studies have been undertaken except in parasitic species. An earlier phylogenetic analysis of protist eIF4Es indicated that they cannot be grouped within the three classes that describe eIF4E family members from multicellular organisms. Many more protist sequences are now available from which three clades can be recognized that are distinct from the plant/fungi/metazoan classes. Understanding of the protist eIF4Es will be facilitated as more sequences become available particularly for the under-represented opisthokonts and amoebozoa. Similarly, a better understanding of eIF4Es within each clade will develop as more functional studies of protist eIF4Es are completed.

No MeSH data available.