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Evolution of selenoproteins in the metazoan.

Jiang L, Ni J, Liu Q - BMC Genomics (2012)

Bottom Line: Amphioxus was found to have the most abundant and variant selenoproteins of any animal currently characterized, including a special selenoprotein P (SelP) possessing 3 repeated Trx-like domains and Sec residues in the N-terminal and 2 Sec residues in the C-terminal.During evolutionary history, only a few new selenoproteins have emerged and few were lost.Furthermore, the massive loss of selenoproteins in nematodes and insects likely occurred independently in isolated partial evolutionary branches.

View Article: PubMed Central - HTML - PubMed

Affiliation: College of Life Sciences, Shenzhen University, Shenzhen, 518060, Guangdong Province, PR, China.

ABSTRACT

Background: The selenocysteine (Sec) containing proteins, selenoproteins, are an important group of proteins present throughout all 3 kingdoms of life. With the rapid progression of selenoprotein research in the post-genomic era, application of bioinformatics methods to the identification of selenoproteins in newly sequenced species has become increasingly important. Although selenoproteins in human and other vertebrates have been investigated, studies of primitive invertebrate selenoproteomes are rarely reported outside of insects and nematodes.

Result: A more integrated view of selenoprotein evolution was constructed using several representative species from different evolutionary eras. Using a SelGenAmic-based selenoprotein identification method, 178 selenoprotein genes were identified in 6 invertebrates: Amphimedon queenslandica, Trichoplax adhaerens, Nematostella vectensis, Lottia gigantean, Capitella teleta, and Branchiostoma floridae. Amphioxus was found to have the most abundant and variant selenoproteins of any animal currently characterized, including a special selenoprotein P (SelP) possessing 3 repeated Trx-like domains and Sec residues in the N-terminal and 2 Sec residues in the C-terminal. This gene structure suggests the existence of two different strategies for extension of Sec numbers in SelP for the preservation and transportation of selenium. In addition, novel eukaryotic AphC-like selenoproteins were identified in sponges.

Conclusion: Comparison of various animal species suggests that even the most primitive animals possess a selenoproteome range and variety similar to humans. During evolutionary history, only a few new selenoproteins have emerged and few were lost. Furthermore, the massive loss of selenoproteins in nematodes and insects likely occurred independently in isolated partial evolutionary branches.

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Selenoproteomes of different animal stages. The evolutionary roles of animals are shown in the schematic phylogenic tree on the left. All animals are abbreviated by 2 letters indicating their Latin names. The selenoprotein families are presented on the top. The red box indicates the existence of a certain family of selenoproteins in an organism. The green box indicates the existence of Cys-form proteins. The blank box indicates that neither selenoprotein nor Cys-form proteins of this family are detected.
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Figure 6: Selenoproteomes of different animal stages. The evolutionary roles of animals are shown in the schematic phylogenic tree on the left. All animals are abbreviated by 2 letters indicating their Latin names. The selenoprotein families are presented on the top. The red box indicates the existence of a certain family of selenoproteins in an organism. The green box indicates the existence of Cys-form proteins. The blank box indicates that neither selenoprotein nor Cys-form proteins of this family are detected.

Mentions: Figure 6 shows selenoproteins of different stages of the animal kingdom, including invertebrates and vertebrates. The schematic phylogenic tree was built based on the phylogeny analysis reported in several genomic research studies of primitive invertebrates, including Amphimedon queenslandica, Trichoplax adhaerens, and Nematostella vectensis[18,41,42]. Seen from the phylogenic tree, the poriferan Amphimedon queenslandica is considered the oldest surviving metazoan, representing the most primitive features of multicellular animals. The placozoan Trichoplax adhaerens and the cnidarian Nematostella vectensis are more evolved animals than sponges, but still very primitive. They are considered the oldest eumetazoan. A more advanced evolutionary stage of the animal kingdom is the bilaterian, with bilateral symmetry. Insects and nematodes belong to a branch of bilaterian named protosotomia. Two other invertebrates, the mollusk Lottia gigantea and the annelid Capitella teleta, analyzed in this work also belong to this phylum. Vertebrates, including humans, are in the phylum deuterostomia. The cephalochordate Branchiostoma floridae, the urochordate Ciona intestinaiis, and vertebrates constitute the chordate, a subphylum of deuterostomia[43,44]. All selenoproteins found in these invertebrates are indicated in Figure 6. Among them are selenoproteins of other reported animals, such as insects, nematodes, and several vertebrates, including fishes, birds, mice, and humans. These are presented in Figure 6 for comparison.


Evolution of selenoproteins in the metazoan.

Jiang L, Ni J, Liu Q - BMC Genomics (2012)

Selenoproteomes of different animal stages. The evolutionary roles of animals are shown in the schematic phylogenic tree on the left. All animals are abbreviated by 2 letters indicating their Latin names. The selenoprotein families are presented on the top. The red box indicates the existence of a certain family of selenoproteins in an organism. The green box indicates the existence of Cys-form proteins. The blank box indicates that neither selenoprotein nor Cys-form proteins of this family are detected.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3473315&req=5

Figure 6: Selenoproteomes of different animal stages. The evolutionary roles of animals are shown in the schematic phylogenic tree on the left. All animals are abbreviated by 2 letters indicating their Latin names. The selenoprotein families are presented on the top. The red box indicates the existence of a certain family of selenoproteins in an organism. The green box indicates the existence of Cys-form proteins. The blank box indicates that neither selenoprotein nor Cys-form proteins of this family are detected.
Mentions: Figure 6 shows selenoproteins of different stages of the animal kingdom, including invertebrates and vertebrates. The schematic phylogenic tree was built based on the phylogeny analysis reported in several genomic research studies of primitive invertebrates, including Amphimedon queenslandica, Trichoplax adhaerens, and Nematostella vectensis[18,41,42]. Seen from the phylogenic tree, the poriferan Amphimedon queenslandica is considered the oldest surviving metazoan, representing the most primitive features of multicellular animals. The placozoan Trichoplax adhaerens and the cnidarian Nematostella vectensis are more evolved animals than sponges, but still very primitive. They are considered the oldest eumetazoan. A more advanced evolutionary stage of the animal kingdom is the bilaterian, with bilateral symmetry. Insects and nematodes belong to a branch of bilaterian named protosotomia. Two other invertebrates, the mollusk Lottia gigantea and the annelid Capitella teleta, analyzed in this work also belong to this phylum. Vertebrates, including humans, are in the phylum deuterostomia. The cephalochordate Branchiostoma floridae, the urochordate Ciona intestinaiis, and vertebrates constitute the chordate, a subphylum of deuterostomia[43,44]. All selenoproteins found in these invertebrates are indicated in Figure 6. Among them are selenoproteins of other reported animals, such as insects, nematodes, and several vertebrates, including fishes, birds, mice, and humans. These are presented in Figure 6 for comparison.

Bottom Line: Amphioxus was found to have the most abundant and variant selenoproteins of any animal currently characterized, including a special selenoprotein P (SelP) possessing 3 repeated Trx-like domains and Sec residues in the N-terminal and 2 Sec residues in the C-terminal.During evolutionary history, only a few new selenoproteins have emerged and few were lost.Furthermore, the massive loss of selenoproteins in nematodes and insects likely occurred independently in isolated partial evolutionary branches.

View Article: PubMed Central - HTML - PubMed

Affiliation: College of Life Sciences, Shenzhen University, Shenzhen, 518060, Guangdong Province, PR, China.

ABSTRACT

Background: The selenocysteine (Sec) containing proteins, selenoproteins, are an important group of proteins present throughout all 3 kingdoms of life. With the rapid progression of selenoprotein research in the post-genomic era, application of bioinformatics methods to the identification of selenoproteins in newly sequenced species has become increasingly important. Although selenoproteins in human and other vertebrates have been investigated, studies of primitive invertebrate selenoproteomes are rarely reported outside of insects and nematodes.

Result: A more integrated view of selenoprotein evolution was constructed using several representative species from different evolutionary eras. Using a SelGenAmic-based selenoprotein identification method, 178 selenoprotein genes were identified in 6 invertebrates: Amphimedon queenslandica, Trichoplax adhaerens, Nematostella vectensis, Lottia gigantean, Capitella teleta, and Branchiostoma floridae. Amphioxus was found to have the most abundant and variant selenoproteins of any animal currently characterized, including a special selenoprotein P (SelP) possessing 3 repeated Trx-like domains and Sec residues in the N-terminal and 2 Sec residues in the C-terminal. This gene structure suggests the existence of two different strategies for extension of Sec numbers in SelP for the preservation and transportation of selenium. In addition, novel eukaryotic AphC-like selenoproteins were identified in sponges.

Conclusion: Comparison of various animal species suggests that even the most primitive animals possess a selenoproteome range and variety similar to humans. During evolutionary history, only a few new selenoproteins have emerged and few were lost. Furthermore, the massive loss of selenoproteins in nematodes and insects likely occurred independently in isolated partial evolutionary branches.

Show MeSH
Related in: MedlinePlus