Acetyl Phosphate Functions
as a Global Signal during Biofilm Development
March, 2003
We used DNA macroarray analysis to identify genes that respond
to the status of the intracellular acetyl phosphate (acP) pool.
Genes whose expression correlated negatively with the ability to
synthesize acP (i.e., negatively regulated genes) function
primarily in flagella biosynthesis, a result consistent with observations
that we published previously [Pruss, 1994 #120]. In contrast, genes
whose expression correlated positively with the ability to synthesize
acP (i.e., positively regulated genes) include those for
type 1 pilus assembly, colanic acid (capsule) biosynthesis, and
certain stress effectors. To our knowledge, this constitutes the
first report that these genes may respond to the status of the intracellular
acP pool. Previously, other researchers had implicated flagella,
type 1 pili, capsule and diverse stress effectors in the formation
of biofilms. We therefore tested whether cells altered in their
ability to metabolize acP could construct normal biofilms, and found
that they could not. Cells defective for the production of acP and
cells defective for the degradation of acP both could form biofilms,
but these biofilms exhibited characteristics substantially different
from each other and from biofilms formed by their wild-type parent.
We confirmed the role of individual cell surface structures, whose
expression appears to correlate with acP levels, in fim
or fli mutants that cannot assemble type I pili or flagella,
respectively. Thus, the information learned by expression profiling
of cells defective for acP production or degradation indicates that
acP may help coordinate expression of surface structures and cellular
processes involved in the initial stages of wild-type biofilm development.
Wolfe, et al., 2003, Mol Microbiol 48: 977-988 (0.3 Kb PDF)
Data Set
The following data set contains the normalized control (conpct)
and test (tstpct) expression values, the log10 expression ratios
(logratio), and P value (pln) (calculated from the LN transformed
normalized raw data) for 6 experimental conditions:
ACP_ACK_AC_V_WT_LO = ackA mutant grown in TB plus 10 mM acetate vs. wildtype grown in TB
ACP_ACK_V_ACK_AC_LO = ackA mutant grown in TB vs. ackA mutant grown in TB plus 10 mM acetate
ACP_ACK_V_PTAACK_LO = ackA mutant grown in TB vs. pta-ackA mutant grown in TB
ACP_ACK_V_WT_LO = ackA mutant grown in TB vs. wildtype grown in TB
ACP_PTAACK_V_ACK_AC_LO = pta-ackA mutant grown in TB vs. ackA mutant grown in TB plus 10 mM acetate
ACP_PTAACK_V_WT_LO = pta-ackA mutant grown in TB vs. wildtype grown in TB
ackA and ackA-pta mutants (Excel: 2.9
Mb)
Supplemental Tables
Supplemental Figure 1: Amino acid utilization
by wildtype, ackA, and pta ackA strains
Supplemental Figure 2: Pellicles formed by wildtype
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