Identification of a novel protein with guanylyl cyclase activity in Arabidopsis thaliana
Abstract
Guanylyl cyclases (GCs) catalyze the formation of the
second messenger guanosine 3 ,5 -cyclic monophos-
phate (cGMP) from guanosine 5 -triphosphate (GTP).
While many cGMP-mediated processes in plants have
been reported, no plant molecule with GC activity has
been identified. When the Arabidopsis thaliana genome
is queried with GC sequences from cyanobacteria, lower
and higher eukaryotes no unassigned proteins with sig-
nificant similarity are found. However, a motif search of
the A. thaliana genome based on conserved and func-
tionally assigned amino acids in the catalytic center of
annotated GCs returns one candidate that also contains
the adjacent glycine-rich domain typical for GCs.