CD50 (ICAM-3) is phosphorylated on tyrosine and is associated with tyrosine kinase activity in human neutrophils

Keith M Skubitz, K. Ahmed, K. D. Campbell, Amy P Skubitz

Research output: Contribution to journalArticle

31 Citations (Scopus)

Abstract

CD50 (ICAM-3) is expressed at a high level on resting blood granulocytes, monocytes, and lymphocytes. The constitutive high expression of CD50 on resting leukocytes suggests that it is an important LFA-1 ligand in the initiation of the immune/inflammatory response. Using a radiolabeling technique initially designed to detect ecto-protein kinase activity, we found that CD50 mAbs immunoprecipitated a ~125- to 170-kDa phosphoprotein from human neutrophils. Phosphorylation was increased after stimulation with the chemotactic agent FMLP, platelet-activating factor, 12-O-tetradecanoyl- phorbol-13-acetate, and the calcium ionophore A23187. This in crease in phosphorylation was transient with the maximal phosphorylation, being observed by 1 min. Phosphoamino acid analysis revealed that CD50 contained predominantly phosphotyrosine. Although this assay system was designed initially to detect ecto-protein kinase activity, subsequent studies have shown that membrane proteins can be phosphorylated on the cytoplasmic domain under these conditions. When CD50 was immunoprecipitated from solubilized neutrophils, protein tyrosine kinase activity associated with CD50 was detected in the immunoprecipitate. The data suggest that phosphorylation of CD50 on tyrosine by an associated tyrosine kinase plays a role in the function of CD50.

Original languageEnglish (US)
Pages (from-to)2888-2895
Number of pages8
JournalJournal of Immunology
Volume154
Issue number6
StatePublished - Jan 1 1995

Fingerprint

Human Activities
Protein-Tyrosine Kinases
Tyrosine
Neutrophils
Phosphorylation
Phosphoamino Acids
Lymphocyte Function-Associated Antigen-1
Phosphotyrosine
Calcium Ionophores
Platelet Activating Factor
Phosphoproteins
Calcimycin
Tetradecanoylphorbol Acetate
Granulocytes
Monocytes
Membrane Proteins
Leukocytes
Lymphocytes
Ligands
ectoprotein kinase

Cite this

CD50 (ICAM-3) is phosphorylated on tyrosine and is associated with tyrosine kinase activity in human neutrophils. / Skubitz, Keith M; Ahmed, K.; Campbell, K. D.; Skubitz, Amy P.

In: Journal of Immunology, Vol. 154, No. 6, 01.01.1995, p. 2888-2895.

Research output: Contribution to journalArticle

@article{a0098113384d4c1786be130e47cc3597,
title = "CD50 (ICAM-3) is phosphorylated on tyrosine and is associated with tyrosine kinase activity in human neutrophils",
abstract = "CD50 (ICAM-3) is expressed at a high level on resting blood granulocytes, monocytes, and lymphocytes. The constitutive high expression of CD50 on resting leukocytes suggests that it is an important LFA-1 ligand in the initiation of the immune/inflammatory response. Using a radiolabeling technique initially designed to detect ecto-protein kinase activity, we found that CD50 mAbs immunoprecipitated a ~125- to 170-kDa phosphoprotein from human neutrophils. Phosphorylation was increased after stimulation with the chemotactic agent FMLP, platelet-activating factor, 12-O-tetradecanoyl- phorbol-13-acetate, and the calcium ionophore A23187. This in crease in phosphorylation was transient with the maximal phosphorylation, being observed by 1 min. Phosphoamino acid analysis revealed that CD50 contained predominantly phosphotyrosine. Although this assay system was designed initially to detect ecto-protein kinase activity, subsequent studies have shown that membrane proteins can be phosphorylated on the cytoplasmic domain under these conditions. When CD50 was immunoprecipitated from solubilized neutrophils, protein tyrosine kinase activity associated with CD50 was detected in the immunoprecipitate. The data suggest that phosphorylation of CD50 on tyrosine by an associated tyrosine kinase plays a role in the function of CD50.",
author = "Skubitz, {Keith M} and K. Ahmed and Campbell, {K. D.} and Skubitz, {Amy P}",
year = "1995",
month = "1",
day = "1",
language = "English (US)",
volume = "154",
pages = "2888--2895",
journal = "Journal of Immunology",
issn = "0022-1767",
publisher = "American Association of Immunologists",
number = "6",

}

TY - JOUR

T1 - CD50 (ICAM-3) is phosphorylated on tyrosine and is associated with tyrosine kinase activity in human neutrophils

AU - Skubitz, Keith M

AU - Ahmed, K.

AU - Campbell, K. D.

AU - Skubitz, Amy P

PY - 1995/1/1

Y1 - 1995/1/1

N2 - CD50 (ICAM-3) is expressed at a high level on resting blood granulocytes, monocytes, and lymphocytes. The constitutive high expression of CD50 on resting leukocytes suggests that it is an important LFA-1 ligand in the initiation of the immune/inflammatory response. Using a radiolabeling technique initially designed to detect ecto-protein kinase activity, we found that CD50 mAbs immunoprecipitated a ~125- to 170-kDa phosphoprotein from human neutrophils. Phosphorylation was increased after stimulation with the chemotactic agent FMLP, platelet-activating factor, 12-O-tetradecanoyl- phorbol-13-acetate, and the calcium ionophore A23187. This in crease in phosphorylation was transient with the maximal phosphorylation, being observed by 1 min. Phosphoamino acid analysis revealed that CD50 contained predominantly phosphotyrosine. Although this assay system was designed initially to detect ecto-protein kinase activity, subsequent studies have shown that membrane proteins can be phosphorylated on the cytoplasmic domain under these conditions. When CD50 was immunoprecipitated from solubilized neutrophils, protein tyrosine kinase activity associated with CD50 was detected in the immunoprecipitate. The data suggest that phosphorylation of CD50 on tyrosine by an associated tyrosine kinase plays a role in the function of CD50.

AB - CD50 (ICAM-3) is expressed at a high level on resting blood granulocytes, monocytes, and lymphocytes. The constitutive high expression of CD50 on resting leukocytes suggests that it is an important LFA-1 ligand in the initiation of the immune/inflammatory response. Using a radiolabeling technique initially designed to detect ecto-protein kinase activity, we found that CD50 mAbs immunoprecipitated a ~125- to 170-kDa phosphoprotein from human neutrophils. Phosphorylation was increased after stimulation with the chemotactic agent FMLP, platelet-activating factor, 12-O-tetradecanoyl- phorbol-13-acetate, and the calcium ionophore A23187. This in crease in phosphorylation was transient with the maximal phosphorylation, being observed by 1 min. Phosphoamino acid analysis revealed that CD50 contained predominantly phosphotyrosine. Although this assay system was designed initially to detect ecto-protein kinase activity, subsequent studies have shown that membrane proteins can be phosphorylated on the cytoplasmic domain under these conditions. When CD50 was immunoprecipitated from solubilized neutrophils, protein tyrosine kinase activity associated with CD50 was detected in the immunoprecipitate. The data suggest that phosphorylation of CD50 on tyrosine by an associated tyrosine kinase plays a role in the function of CD50.

UR - http://www.scopus.com/inward/record.url?scp=0028919591&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0028919591&partnerID=8YFLogxK

M3 - Article

C2 - 7876557

AN - SCOPUS:0028919591

VL - 154

SP - 2888

EP - 2895

JO - Journal of Immunology

JF - Journal of Immunology

SN - 0022-1767

IS - 6

ER -