Biology Faculty Articles
Document Type
Article
Publication Date
11-2011
Publication Title
BMC Evolutionary Biology
ISSN
1471-2148
Volume
11
Issue/No.
342
First Page
1
Last Page
23
Abstract
Background
Matrix extracellular phosphoglycoprotein (MEPE) belongs to a family of small integrin-binding ligand N-linked glycoproteins (SIBLINGs) that play a key role in skeleton development, particularly in mineralization, phosphate regulation and osteogenesis. MEPE associated disorders cause various physiological effects, such as loss of bone mass, tumors and disruption of renal function (hypophosphatemia). The study of this developmental gene from an evolutionary perspective could provide valuable insights on the adaptive diversification of morphological phenotypes in vertebrates.
Results
Here we studied the adaptive evolution of the MEPE gene in 26 Eutherian mammals and three birds. The comparative genomic analyses revealed a high degree of evolutionary conservation of some coding and non-coding regions of the MEPE gene across mammals indicating a possible regulatory or functional role likely related with mineralization and/or phosphate regulation. However, the majority of the coding region had a fast evolutionary rate, particularly within the largest exon (1467 bp). Rodentia and Scandentia had distinct substitution rates with an increased accumulation of both synonymous and non-synonymous mutations compared with other mammalian lineages. Characteristics of the gene (e.g. biochemical, evolutionary rate, and intronic conservation) differed greatly among lineages of the eight mammalian orders. We identified 20 sites with significant positive selection signatures (codon and protein level) outside the main regulatory motifs (dentonin and ASARM) suggestive of an adaptive role. Conversely, we find three sites under selection in the signal peptide and one in the ASARM motif that were supported by at least one selection model. The MEPE protein tends to accumulate amino acids promoting disorder and potential phosphorylation targets.
Conclusion
MEPE shows a high number of selection signatures, revealing the crucial role of positive selection in the evolution of this SIBLING member. The selection signatures were found mainly outside the functional motifs, reinforcing the idea that other regions outside the dentonin and the ASARM might be crucial for the function of the protein and future studies should be undertaken to understand its importance.
Additional Comments
Fundação para a Ciência e a Tecnologia grant and project #s: SFRH/BD/65245/2009, PTDC/BIA-BDE/69144/2006 (FCOMP-01-0124-FEDER-007065), PTDC/AAC-AMB/104983/2008 (FCOMP-01-0124-FEDER-008610)
NSUWorks Citation
Machado, Joao P.; Warren E. Johnson; Stephen J. O'Brien; Vitor Vasconcelos; and Agostinho Antunes. 2011. "Adaptive Evolution of the Matrix Extracellular Phosphoglycoprotein in Mammals." BMC Evolutionary Biology 11, (342): 1-23. https://nsuworks.nova.edu/cnso_bio_facarticles/753
ORCID ID
0000-0001-7353-8301
ResearcherID
N-1726-2015
Comments
©Machado et al; licensee BioMed Central Ltd. 2011