Characterization of Chelation and Absorption of Calcium by a Mytilus edulis Derived Osteogenic Peptide.

In a previous study, the peptide LGKDQVRT, which was identified by enzymatic hydrolysis, released during the proteolysis of Mytilus edulis, had potential osteogenic activity. In this study, the octapeptide LGKDQVRT was able to spontaneously bind calcium in a 1:1 stoichiometric ratio, and the calcium-binding site likely involves calcium and amino acid VAL6 in the LGKDQVRT peptide to form a metal-donor to metal acceptor complex. The peptide LGKDQVRT has the activity of promoting the proliferation and differentiation of osteoblasts. The results of this study suggest that hydrolyzed peptides from Mytilus edulis protein can be used as a dietary supplement to improve calcium absorption and prevent osteoporosis.

Application of a Mytilus edulis-derived promoting calcium absorption peptide in calcium phosphate cements for bone.

The IEELEEELEAER peptide (PIE) identified from the protein hydrolysate of Mytilus edulis is reported to enhance osteoblast growth and differentiation, which also possesses a superior bone formation ability both in vitro and in vivo. Moreover, PIE bound to calcium spontaneously at the stoichiometry of 1:1, and there were amino nitrogen and carboxyl oxygen atoms in 2 glutamic acid residues at the calcium-binding sites in the PIE. The PIE-calcium complex facilitated calcium uptake through the Caco-2 cell monolayers. Incorporation of PIE into calcium phosphate cements enhanced calcium ion uptake and proliferation of osteoblasts and inhibit bacteria. This study suggest that calcium phosphate cements supplemented with PIE can serve as a potentially efficient material for bone graft used during spinal surgery.

The transcription factor GATA10 regulates fertility conversion of a two-line hybrid tms5 mutant rice via the modulation of UbL40 expression.

The thermosensitive genic male sterile 5 (tms5) mutation causes thermosensitive genic male sterility in rice (Oryza sativa) through loss of RNase ZS1 function, which influences ubiquitin fusion ribosomal protein L40 (UbL40 ) messenger RNA levels during male development. Here, we used ATAC-seq, combined with analysis of H3K9ac and H3K4me2, to identify changes in accessible chromatin during fertility conversion of the two-line hybrid rice Wuxiang S (WXS) derived from a mutant tms5 allele. Furthermore, RNA-seq and bioinformatic analyses identified specific transcription factors (TFs) in differentially accessible chromatin regions. Among these TFs, only GATA10 targeted UbL40 . Osgata10 knockout mutations, which resulted in low expression of UbL40 and a tendency toward male fertility, confirmed that GATA10 regulated fertility conversion via the modulation of UbL40 . Meanwhile, GATA10 acted as a mediator for interactions with ERF65, which revealed that transcriptional regulation is a complex process involving multiple complexes of TFs, namely TF modules. It appears that the ERF141/MADS7/MADS50/MYB modules affect metabolic processes that control anther and pollen development, especially cell wall formation. Our analysis revealed that these modules directly or indirectly affect metabolic pathway-related genes to coordinate plant growth with proper anther development, and furthermore, that GATA10 regulates fertility conversion via the modulation of UbL40 expression.