Expression of interleukin-2 receptor gamma on human monocytes: characterization of lineage specific post-translational modifications.
Functional interleukin-2 receptors (IL-2R) on lymphocytes contain both IL-2R beta and gamma chains. Whereas constitutive expression of IL-2R beta has been found on monocytes, the expression of IL-2R gamma on these phagocytes has not been examined. We performed reverse-transcription-polymerase chain reaction with Southern blot analysis on RNA derived from purified human monocytes and discovered that they constitutively produce IL-2R gamma mRNA. Western immunoblotting revealed 58- and 64-kDa forms of IL-2R gamma on YT-1 and human monocytes, whereas 58-, 64-, and 69-kDa bands were detected using peripheral blood mononuclear cells and non-adherent lymphocytes. These different forms resulted from variable N-linked glycosylation since culture of the cells in tunicamycin resulted in detection of a single 39-kDa band which corresponds to the molecular weight predicted from the deduced amino acid sequence. By co-immunoprecipitation, the IL-2R beta subunit associates with only the 64-kDa IL-2R gamma protein band in monocytes.
H. Lee Moffitt Cancer Center and Research Institute, Immunology Research Program, Tampa, FL 33612.
P K
PK
Epling-Burnette
S
S
Wei
J H
JH
Liu
F
F
Pericle
D
D
Ussery
S M
SM
Russell
W J
WJ
Leonard
J Y
JY
Djeu
D015139:Blotting, Southern; D015153:Blotting, Western; D006801:Humans; D066298:In Vitro Techniques; D009000:Monocytes / Q000276:immunology*; D016133:Polymerase Chain Reaction; D011233:Precipitin Tests; D011499:Protein Processing, Post-Translational / Q000502:physiology*; D012333:RNA, Messenger / Q000096:biosynthesis*; D015375:Receptors, Interleukin-2 / Q000096:biosynthesis* / Q000378:metabolism
D012333:RNA, Messenger; D015375:Receptors, Interleukin-2