Actin: a target of lipopolysaccharide-induced phosphorylation in human monocytes.
We have previously reported that lipopolysaccharide (LPS) causes altered phosphate labelling of cytosolic proteins of 36 kDa and 38 kDa (p36/38) and that inhibition of phosphorylation is accompanied by a loss of cytokine production. Here we have purified the two phosphorylated proteins via two-dimensional polyacrylamide gel electrophoresis. P 36 was found to consist of two proteins p36a and p36b. The proteins were analysed by matrix-assisted laser desorption ionization (MALDI) mass spectrometry and p36b was identified as gamma-actin, p36a as beta/gamma-actin. The ability of LPS to cause altered phosphate labelling of beta/gamma-actin suggests a participation of the microfilament network in LPS-induced monocyte activation.
Hauschildt
S
S
Department of Immunobiology, University of Leipzig, Germany.
Schwarz
C
C
Heine
H
H
Ulmer
A J
AJ
Flad
H D
HD
Rietschel
E T
ET
Jensen
O N
ON
Mann
M
M
D000199:Actins / Q000302:isolation & purification / Q000378:metabolism*; D000595:Amino Acid Sequence; D003600:Cytosol / Q000378:metabolism; D006801:Humans; D007536:Isomerism; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008262:Macrophage Activation; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009000:Monocytes / Q000187:drug effects / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D000199:Actins; D008070:Lipopolysaccharides