PMID- 15561724
OWN - NLM
STAT- MEDLINE
DCOM- 20050418
LR  - 20240109
IS  - 0021-9258 (Print)
IS  - 0021-9258 (Linking)
VI  - 280
IP  - 7
DP  - 2005 Feb 18
TI  - NDPK2 as a signal transducer in the phytochrome-mediated light signaling.
PG  - 5740-9
AB  - Nucleoside-diphosphate kinase (NDPK) 2 in Arabidopsis has been identified as a 
      phytochrome-interacting protein by using the C-terminal domain of phytochrome A 
      (PhyA) as the bait in yeast two-hybrid screening. The far-red light-absorbing 
      form of phytochrome (Pfr) A stimulates NDPK2 gamma-phosphate exchange activity in 
      vitro. To better understand the multiple functions of NDPK and its role in 
      phytochrome-mediated signaling, we characterized the interaction between 
      phytochrome and NDPK2. Domain studies revealed that PER-ARNT-SIM domain A in the 
      C-terminal domain of phytochrome is the binding site for NDPK2. Additionally, 
      phytochrome recognizes both the NDPK2 C-terminal fragment and the NDPK2 hexameric 
      structure to fulfill its binding. To illustrate the mechanism of how the Pfr form 
      of phytochrome stimulates NDPK2, His-197-surrounding residue mutants were made 
      and tested. Results suggested that the H-bonding with His-197 inside the 
      nucleotide-binding pocket is critical for NDPK2 functioning. The pH dependence 
      profiles of NDPK2 indicated that mutants with different activities from the wild 
      type have different pK(a) values of His-197 and that NDPK2 hyperactive mutants 
      possess lower pK(a) values. Because a lower pK(a) value of His-197 accelerates 
      NDPK2 autophosphorylation and the phospho-transfer between the phosphorylated 
      NDPK2 and its kinase substrate, we concluded that the Pfr form of phytochrome 
      stimulates NDPK2 by lowering the pK(a) value of His-197.
FAU - Shen, Yu
AU  - Shen Y
AD  - Department of Chemistry, University of Nebraska, Lincoln, NE 68588-0304, USA.
FAU - Kim, Jeong-Il
AU  - Kim JI
FAU - Song, Pill-Soon
AU  - Song PS
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20041123
PL  - United States
TA  - J Biol Chem
JT  - The Journal of biological chemistry
JID - 2985121R
RN  - 0 (Phosphates)
RN  - 11121-56-5 (Phytochrome)
RN  - 146-91-8 (Guanosine Diphosphate)
RN  - 8L70Q75FXE (Adenosine Triphosphate)
RN  - EC 2.7.4.- (nucleoside diphosphate kinase 2)
RN  - EC 2.7.4.6 (Nucleoside-Diphosphate Kinase)
SB  - IM
MH  - Adenosine Triphosphate/metabolism
MH  - Arabidopsis/enzymology/*metabolism/*radiation effects
MH  - Binding Sites
MH  - Dimerization
MH  - Enzyme Stability
MH  - Guanosine Diphosphate/metabolism
MH  - Hydrogen-Ion Concentration
MH  - *Light
MH  - Mutation/genetics
MH  - Nucleoside-Diphosphate Kinase/chemistry/genetics/*metabolism
MH  - Phosphates/metabolism
MH  - Phosphorylation
MH  - Phytochrome/chemistry/*metabolism
MH  - Protein Binding
MH  - Protein Structure, Quaternary
MH  - Signal Transduction/*radiation effects
EDAT- 2004/11/25 09:00
MHDA- 2005/04/19 09:00
CRDT- 2004/11/25 09:00
PHST- 2004/11/25 09:00 [pubmed]
PHST- 2005/04/19 09:00 [medline]
PHST- 2004/11/25 09:00 [entrez]
AID - S0021-9258(19)63078-4 [pii]
AID - 10.1074/jbc.M408965200 [doi]
PST - ppublish
SO  - J Biol Chem. 2005 Feb 18;280(7):5740-9. doi: 10.1074/jbc.M408965200. Epub 2004 
      Nov 23.