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Identification CD79a and CD79b homologs in channel catfish, Ictaulurus punctatus
Author(s) -
Sahoo Manoranjan,
Edholm Evastina,
Stafford James,
Bengten Eva,
Miller Norman W.,
Wilson Melanie
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.863.7
Subject(s) - catfish , biology , microbiology and biotechnology , immunoglobulin domain , transmembrane domain , transmembrane protein , immunoreceptor tyrosine based activation motif , epitope , antibody , gene , transfection , immunoprecipitation , signal peptide , tyrosine kinase , receptor , peptide sequence , signal transduction , genetics , sh2 domain , fishery , fish <actinopterygii>
The catfish (Ip) B cell receptor accessory molecules CD79a and CD79b homologs have been identified. Each are encoded by single copy genes that encode proteins containing a signal peptide, an extracellular immunoglobulin domain, a transmembrane region and a cytoplasmic tail containing an immunoreceptor tyrosine kinase activation motif (ITAM). At the message level, both IpCD79a and IpCD79b correlate well with IgM message expression since they are highly expressed in membrane IgM + peripheral blood leukocytes (PBL) and in catfish clonal B cell lines, but not in IgM − PBL or in clonal T cells or macrophages. Such findings indicate that IpCD79a and IpCD79b expression is B cell restricted. Furthermore, studies using catfish clonal B cells (3B11) transfected with constructs encoding epitope‐tagged IpCD79 proteins revealed that IpCD79a is expressed as a 45 kDa protein and IpCD79b is expressed as a 32 kDa protein. These correlate with the molecular weights of putative tyrosine phosphorylated accessory proteins that are co‐immunoprecipitated with surface IgM following anti‐Ig stimulation. Supported by NIH grant R01 AI19530 .