With this new mapping of royal jelly proteins, future studies will examine not only the antimicrobial aspects of this magnificent product produced for the queen, but numerous other beneficial effects already documented.
All eight overlapping
phosphoproteins showed significantly higher abundance in Acc-RJ than in Aml-RJ,
and the phosphorylation of Jelleine-II (an antimicrobial peptide, TPFKLSLHL) at
S6 in Acc-RJ had stronger antimicrobial properties than that at T1 in Aml-RJ even
though the overall antimicrobial activity of Jelleine-II was found to decrease
after phosphorylation. The differences in phosphosites, peptide abundance, and
antimicrobial activity of the phosphorylated RJ proteins indicate that the two
major honeybee species employ distinct phosphorylation strategies that align
with their different biological characteristics shaped by evolution. The
phosphorylation of RJ proteins are potentially driven by the activity of
extracellular serine/threonine protein kinase FAM20C-like protein (FAM20C-like)
through the [S-x-E] motif, which is supported by evidence that mRNA and protein
expression of FAM20C-like protein kinase are both found in the highest level in
the hypopharyngeal gland of nurse bees.
In-Depth Phosphoproteomic Analysis of Royal Jelly Derived
from Western and Eastern Honeybee Species
J. Proteome Res., 2014, 13 (12), pp 5928–5943
The proteins in royal jelly (RJ) play a pivotal role in the
nutrition, immune defense, and cast determination of honeybee larvae and have a
wide range of pharmacological and health-promoting functions for humans as
well. Although the importance of post-translational modifications (PTMs) in
protein function is known, investigation of protein phosphorylation of RJ
proteins is still very limited.
To this end, two complementary phosphopeptide enrichment
materials (Ti4+-IMAC and TiO2) and high-sensitivity mass spectrometry were
applied to establish a detailed phosphoproteome map and to qualitatively and
quantitatively compare the phosphoproteomes of RJ produced by Apis mellifera ligustica
(Aml) and Apis cerana cerana (Acc). In total, 16 phosphoproteins carrying 67
phosphorylation sites were identified in RJ derived from western bees, and nine
proteins phosphorylated on 71 sites were found in RJ produced by eastern
honeybees. Of which, eight phosphorylated proteins were common to both RJ
samples, and the same motif ([S-x-E]) was extracted, suggesting that the
function of major RJ proteins as nutrients and immune agents is evolutionary
preserved in both of these honeybee species.
All eight overlapping
phosphoproteins showed significantly higher abundance in Acc-RJ than in Aml-RJ,
and the phosphorylation of Jelleine-II (an antimicrobial peptide, TPFKLSLHL) at
S6 in Acc-RJ had stronger antimicrobial properties than that at T1 in Aml-RJ even
though the overall antimicrobial activity of Jelleine-II was found to decrease
after phosphorylation. The differences in phosphosites, peptide abundance, and
antimicrobial activity of the phosphorylated RJ proteins indicate that the two
major honeybee species employ distinct phosphorylation strategies that align
with their different biological characteristics shaped by evolution. The
phosphorylation of RJ proteins are potentially driven by the activity of
extracellular serine/threonine protein kinase FAM20C-like protein (FAM20C-like)
through the [S-x-E] motif, which is supported by evidence that mRNA and protein
expression of FAM20C-like protein kinase are both found in the highest level in
the hypopharyngeal gland of nurse bees.
Our data represent the first comprehensive RJ
phosphorylation atlas, recording patterns of phosphorylated RJ protein
abundance and antibacterial activity of some RJ proteins in two major managed
honeybee species. These data constitute a firm basis for future research to
better understand the biological roles of each RJ protein for honeybee biology
and human health care.
