Dataset Information

Molecular Evolution and Expression Divergence of HMT Gene Family in Plants.

ABSTRACT: Homocysteine methyltransferase (HMT) converts homocysteine to methionine using S-methylmethionine (SMM) or S-adenosylmethionine (SAM) as methyl donors in organisms, playing an important role in supplying methionine for the growth and the development of plants. To better understand the functions of the HMT genes in plants, we conducted a wide evolution and expression analysis of these genes. Reconstruction of the phylogenetic relationship showed that the HMT gene family was divided into Class 1 and Class 2. In Class 1, HMTs were only found in seed plants, while Class 2 presented in all land plants, which hinted that the HMT genes might have diverged in seed plants. The analysis of gene structures and selection pressures showed that they were relatively conserved during evolution. However, type I functional divergence had been detected in the HMTs. Furthermore, the expression profiles of HMTs showed their distinct expression patterns in different tissues, in which some HMTs were widely expressed in various organs, whereas the others were highly expressed in some specific organs, such as seeds or leaves. Therefore, according to our results in the evolution, functional divergence, and expression, the HMT genes might have diverged during evolution. Further analysis in the expression patterns of AthHMTs with their methyl donors suggested that the diverged HMTs might be related to supply methionine for the development of plant seeds.

SUBMITTER: Zhao M

PROVIDER: S-EPMC5979542 | biostudies-literature | 2018 Apr

REPOSITORIES: biostudies-literature

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Molecular Evolution and Expression Divergence of HMT Gene Family in Plants.

Zhao Man M Chen Peng P Wang Wenyi W Yuan Fengjie F Zhu Danhua D Wang Zhao Z Ying Xiangxian X

International journal of molecular sciences 20180420 4

Homocysteine methyltransferase (HMT) converts homocysteine to methionine using S-methylmethionine (SMM) or S-adenosylmethionine (SAM) as methyl donors in organisms, playing an important role in supplying methionine for the growth and the development of plants. To better understand the functions of the HMT genes in plants, we conducted a wide evolution and expression analysis of these genes. Reconstruction of the phylogenetic relationship showed that the HMT gene famil ...[more]

PMID: 29677135

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Project description:IgLON family is a subgroup of cell adhesion molecules which is known to have diverse roles in neuronal development. IgLONs are characterized by possessing 3 Ig-like C2 domains, which play a part in mediating various cellular interactions. Recently, IgLONs have been shown to be expressed at the blood-brain barrier (BBB). However, our understanding of the genetic divergence patterns and evolutionary rates of these proteins in relation to their functions, in general, and at the BBB, in particular, remains inadequate. In this study, 12 species were explored to shed more light on the phylogenetic origins, structure, functional specificity, and divergence of this family. A total of 40 IgLON genes were identified from vertebrates and invertebrates. The absence of IgLON family genes in Hydra vulgaris and Nematostella vectensis but not in Drosophila melanogaster suggests that this family appeared during the time of divergence of Arthropoda 455?Mya. In general, IgLON genes have been subject to strong positive selection in vertebrates. Our study, based on IgLONs' structural similarity, suggests that they may play a role in the evolutionary changes in the brain anatomy towards complexity including regulating neural growth and BBB permeability. IgLONs' functions seem to be performed through complex interactions on the level of motifs as well as single residues. We identified several IgLON motifs that could be influencing cellular migration and proliferation as well as BBB integrity through interactions with SH3 or integrin. Our motif analysis also revealed that NEGR1 might be involved in MAPK pathway as a form of a signal transmitting receptor through its motif (KKVRVVVNF). We found several residues that were both positively selected and with highly functional specificity. We also located functional divergent residues that could act as drug targets to regulate BBB permeability. Furthermore, we identified several putative metalloproteinase cleavage sites that support the ectodomain shedding hypothesis of the IgLONs. In conclusion, our results present a bridge between IgLONs' molecular evolution and their functions.

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Dataset Information

Molecular Evolution and Expression Divergence of HMT Gene Family in Plants.

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Molecular Evolution and Expression Divergence of <i>HMT</i> Gene Family in Plants.

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