RT Journal Article
SR Electronic
T1 Interactions of bacterial lipopolysaccharide with microtubule proteins.
JF The Journal of Immunology
JO J. Immunol.
FD American Association of Immunologists
SP 2853
OP 2858
VO 148
IS 9
A1 Ding, A
A1 Sanchez, E
A1 Tancinco, M
A1 Nathan, C
YR 1992
UL http://www.jimmunol.org/content/148/9/2853.abstract
AB Bacterial LPS is a potent stimulator of immune cells, but its mechanisms are unknown. A possible role for microtubules in LPS actions has been indicated by previous findings that the microtubule-active agent, taxol, can mimic some effects of LPS in macrophages from normal strains of mice, but not from genetically LPS-hyporesponsive strains. In this report we demonstrate that isolated microtubules from mouse brain can bind LPS in vitro. LPS and tubulin coeluted through a gel filtration column, and LPS was cross-linked to microtubule proteins with an iodinatable, photoreactive agent, sulfosuccinimidyl 2-(p-azidosalicylamido) ethyl-1,3'-dithiopropionate. beta-Tubulin and microtubule-associated protein-2 (MAP), a predominant MAP in the brain, bound LPS specifically. Cross-linking was inhibited by an excess of unlabeled LPS or partially by unlabeled lipid A, but not by 2 M NaCl. Under the same conditions, neither myosin nor soybean trypsin inhibitor was labeled by the photoaffinity LPS probe, nor did these proteins compete for binding of LPS to beta-tubulin. These findings support the hypothesis that the microtubule network could be an intracellular target for LPS, and suggest further that a beta-tubulin-associated MAP could have an important role in LPS actions.