Acylation of cell-associated IL-1 by palmitic acid

• Published in: The Journal of immunology (1950) Vol. 147; no. 7; pp. 2164 - 2169
• Main Authors: Bakouche, O, Moreau, JL, Lachman, LB
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Am Assoc Immnol 01.10.1991; American Association of Immunologists
• Subjects: Acylation; Analysis of the immune response. Humoral and cellular immunity; Autoradiography; Biological and medical sciences; Blotting, Western; Cells, Cultured; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Glycosylation; Humans; Immunobiology; Interleukin-2 - metabolism; Lymphokines, interleukins ( function, expression); Membrane Proteins - immunology; Palmitic Acid; Palmitic Acids - metabolism; Precipitin Tests; Regulatory factors and their cellular receptors; Human; Immunoprecipitation reaction; Chemical modification; Membrane protein; Monocyte; Cytokine; Interleukin 1; Plasma membrane; Lipopolysaccharide; Palmitic acid; Acylation
• ISSN: 0022-1767; 1550-6606
• DOI: 10.4049/jimmunol.147.7.2164

To determine whether membrane-associated IL-1 is palmitylated, we labeled LPS-activated human monocytes with [3H]palmitic acid. The plasma membranes were isolated, and the membrane proteins extracted and analyzed simultaneously by SDS-PAGE-autoradiography and Western blot analysis from the same gel. When the monocytes were labeled with [3H]palmitate, 23- and 31-kDa bands were visualized, for membrane-associated IL-1 and its precursor, respectively. The 31- and 23-kDa bands were excised from several gels and rehydrated and analyzed again by SDS-PAGE, autoradiography, and Western blot analysis. The 23- and 31-kDa bands appeared again by both methods. To further investigate membrane-associated IL-1 acylation, human monocytes were labeled with [3H]palmitate, the plasma membranes isolated, and the membrane proteins extracted by CHAPS detergent. Immunoprecipitation of isolated membrane proteins using anti-IL-1 antibodies revealed two bands of 23 and 31 kDa after autoradiography. The studies demonstrate that both membrane-associated IL-1 and the IL-1 precursor are acylated with palmitic acid.