Proteomic Approach to FcepsilonRI aggregation-initiated signal transduction cascade in human mast cells.
BACKGROUND
Mast cells (MCs) play a central role in allergic reactions through high-affinity IgE receptor (FcepsilonRI)-mediated responses. Many attempts have been performed to investigate MC functions, though molecular bases of the intracellular signaling cascade through FcepsilonRI, especially in human MCs, remain scant and unexplored.


METHODS
Human MCs were differentiated from CD34+ cells by culture with stem cell factor, IL-6 and IL-3. The differential phosphorylation profiles of protein tyrosine residues in the resulting MCs with or without FcepsilonRI aggregation were examined by two-dimensional gel electrophoresis. The candidate phosphoproteins of interest were picked, in-gel digested and mass spectrometry fingerprinted.


RESULTS
Approximately 40 proteins in MCs were phosphorylated on their tyrosine residues in response to activation and some of them were identified. Particularly IL-31 receptor alpha, solute carrier family 39, syntaxin 5 and heterogeneous nuclear ribonucleoprotein are newly identified as phosphoproteins that are potentially involved in the MC signaling cascade through FcepsilonRI.


CONCLUSIONS
Our present phosphoproteome data may provide the clue to understand the molecular mechanisms for the activation of human MCs.
Yamaoka
Kazuko
K
Department of Allergy and Immunology, Tokyo Metropolitan Institute of Medical Science, 3-18-22 Honkomagome, Bunkyoku, Tokyo 113-8613, Japan. yamaoka-kz@igakuken.or.jp
Okayama
Yoshimichi
Y
Kaminuma
Osamu
O
Katayama
Kazufumi
K
Mori
Akio
A
Tatsumi
Hideki
H
Nemoto
Sohichi
S
Hiroi
Takachika
T
D027682:Cation Transport Proteins / Q000378:metabolism; D034441:Heterogeneous-Nuclear Ribonucleoproteins / Q000378:metabolism; D006801:Humans; D008407:Mast Cells / Q000378:metabolism*; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation; D040901:Proteomics; D050765:Qa-SNARE Proteins / Q000378:metabolism; D017455:Receptors, IgE / Q000378:metabolism*; D018123:Receptors, Interleukin / Q000378:metabolism; D015398:Signal Transduction; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014443:Tyrosine / Q000378:metabolism*
D027682:Cation Transport Proteins; D034441:Heterogeneous-Nuclear Ribonucleoproteins; C502188:IL31RA protein, human; C502447:MS4A2 protein, human; D010750:Phosphoproteins; D050765:Qa-SNARE Proteins; D017455:Receptors, IgE; D018123:Receptors, Interleukin; D014443:Tyrosine