NEUTROPHIL ACTIVATION OF THE OXIDATIVE BURST

Project: Research project

Project Details

Description

The polymorphonuclear leukocyte (PMN) carries out its critical microbicidal
functions in large part through a stimulus-induced burst of oxidative
metabolism which generates superoxide anion and other toxic products of
oxygen. An activatable NADPH oxidase system responsible for oxygen
reduction does not function in the cells of patients with chronic
granulomatous disease (CGD). Studies in a reconstituted cell-free oxidase
system have demonstrated requirements for components in the membrane (e.g.
cytochrome b558) and the cytosol. Recent studies have identified two
discrete cytosolic oxidase components,, proteins of 47 and 67 kDa, and
demonstrated selective absence of one or the other of these protein from
the PMN of patients with two different types of autosomal CGD. Based on
the recent cloning of both p47 and p67 as well as sequencing and functional
expression of the p47 cDNAs, detailed studies of structure/function
relationships and the genetic determinants of autosomal CGD are proposed.
Synthetic peptides and recombinant proteins including deletion and site-
directed mutants will be examined in defined cell-free systems in order to
map the structural determinants of function to specific domains within the
two proteins. Specific considerations for p5=47 will include sites and
mechanisms of stimulus-dependent phosphorylation, N-myristoylation of the
N-terminal glycine, potential regulatory role of a region homologous to the
src oncogene family, and determinants of GTP binding. The sequencing of
the p67 clones will be completed and, based on predicted amino acid
sequence, structure/function relationships will be assessed including the
basis for GTP binding and the potential presence of a substrate (NADPH)
binding site. Patients with autosomal CGD attributable to p47 or p67
deficiency will be studied at the levels of DNA, mRNA and protein in order
to define the genetic basis for the deficiencies. These proposed studies
will contribute to a fundamental understanding of the human neutrophil
NADPH oxidase system at a molecular level and to a definition of the
genetic basis for the microbicidal defect in patients with autosomal CGD.
StatusFinished
Effective start/end date8/1/835/31/07

Funding

  • National Institutes of Health: $330,644.00
  • National Institutes of Health: $305,698.00
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health: $361,250.00
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health: $249,218.00
  • National Institutes of Health
  • National Institutes of Health: $282,635.00
  • National Institutes of Health
  • National Institutes of Health: $361,250.00
  • National Institutes of Health: $307,063.00
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health: $361,250.00
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health: $361,250.00

ASJC

  • Medicine(all)
  • Immunology and Microbiology(all)

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