Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:4.6.1.1 (
adenylate cyclase
)
19,190
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Potassium (K
+
) is the most abundant cation in plants, and its uptake and transport are key to growth, development and responses to the environment. Here, we report that
Arabidopsis thaliana
K
+
uptake permease 5 (AtKUP5) contains an
adenylate cyclase
(AC) catalytic center embedded in its N-terminal cytosolic domain. The purified recombinant AC domain generates cAMP
in vitro
; and when expressed in
Escherichia coli
, increases cAMP levels
in vivo
. Both the AC domain and full length AtKUP5 rescue an AC-deficient
E. coli
mutant,
cyaA
, and together these data provide evidence that AtKUP5 functions as an AC. Furthermore, full length AtKUP5 complements the
Saccharomyces cerevisiae
K
+
transport impaired mutant,
trk1
trk2
, demonstrating its function as a K
+
transporter. Surprisingly, a point mutation in the AC center that impairs AC activity, also abolishes complementation of
trk1
trk2
, suggesting that a functional catalytic AC domain is essential for K
+
uptake. AtKUP5-mediated K
+
uptake is not affected by cAMP, the catalytic product of the AC, but, interestingly, causes cytosolic cAMP accumulation. These findings are consistent with a role for AtKUP5 as K
+
flux sensor, where the flux-dependent cAMP increases modulate downstream components essential for K
+
homeostasis, such as cyclic nucleotide gated channels.
...
PMID:The
Arabidopsis thaliana
K
+
-Uptake Permease 5 (AtKUP5) Contains a Functional Cytosolic Adenylate Cyclase Essential for K
+
Transport. 3048 96
