RT Journal Article
SR Electronic
T1 Identification and characterization of a novel surface antigen gene induced in mast cells activated through the high affinity IgE receptor.
JF The Journal of Immunology
JO J. Immunol.
FD American Association of Immunologists
SP 5811
OP 5818
VO 155
IS 12
A1 Pirozzi, G
A1 Terry, R W
A1 Epstein, D
A1 Labow, M A
YR 1995
UL http://www.jimmunol.org/content/155/12/5811.abstract
AB In an effort to isolate novel genes involved in inflammation and/or mast cell activation, we have used a combination of differential screening and subtractive hybridization to isolate genes whose expression are induced upon activation of a transformed rat mast cell line. One of the isolated clones, pMCA-32, contained an open reading frame of 278 amino acids that included a putative hydrophobic transmembrane domain, a cysteine rich Ig-like extracellular domain, and a cytoplasmic domain containing three consensus SH2-domain phosphotyrosine binding sites. The MCA-32 gene is also highly conserved between rat and mouse, with the two coding regions being 73% identical. Although the MCA-32 coding region did not contain an obvious signal peptide, MCA-32 protein was detected on the surface of rat mast cells, and the cloned cDNA produced a cell surface protein when expressed in COS-7 cells. MCA-32 RNA from both mouse and rat undergoes alternative splicing, producing an mRNA containing an in-frame deletion of the TM domain, suggesting that a form of MCA-32 protein may be secreted. MCA-32 mRNA expression was up-regulated upon activation of RBL-2H3 cells and was highly abundant in primary peritoneal mast cells. Expression of MCA-32 RNA was only observed in primary and transformed mast cells from rat, while in the mouse MCA-32, RNA was also produced in significant amounts by a number of transformed monocyte cell lines. Thus, MCA-32 is a novel surface protein whose structure and expression suggest roles in the development and/or activation of mast cells and monocytes.