Open AccessIntracytoplasmic phosphorylation sites of Tac antigen (p55) are not essential for the conformation, function, and regulation of the human interleukin 2 receptor.
Author(s) -
Masanori Hatakeyama,
Seijiro Minamoto,
Tadatsugu Taniguchi
Publication year - 1986
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.83.24.9650
Subject(s) - phosphorylation , interleukin 13 receptor , receptor , 5 ht5a receptor , biology , enzyme linked receptor , interleukin 21 receptor , signal transduction , microbiology and biotechnology , protease activated receptor 2 , interleukin 4 receptor , serine , biochemistry , phosphorylation cascade , protein phosphorylation , protein kinase a , insulin like growth factor 1 receptor , growth factor
Tac antigen, the receptor for human interleukin 2 (IL-2), contains in its intracytoplasmic region a serine residue (Ser-247) that is seemingly the predominant site of protein kinase C-mediated phosphorylation. A number of studies on growth factor receptors have suggested the importance of phosphorylation in receptor structure, function, and regulation. In this study, we generated site-directed mutations in the Tac antigen cDNA to generate mutant receptors in which Ser-247 or Thr-250, a probable site of minor phosphorylation, was replaced with another amino acid that is not accessible to phosphorylation. Study of the expression of these mutant genes in a T-lymphoid cell line has provided no evidence as to the essential role of the above-mentioned residues in determining the degree of receptor affinity, its ability for signal transduction, and phorbol ester-mediated regulation of the receptor. Our results strongly suggest the existence of an IL-2 receptor "complex" in which the Tac antigen is associated with another molecule(s) that is involved in receptor structure, function, and regulation.