PMID- 17572840
OWN - NLM
STAT- MEDLINE
DCOM- 20080327
LR  - 20181113
IS  - 1431-0651 (Print)
IS  - 1431-0651 (Linking)
VI  - 11
IP  - 6
DP  - 2007 Nov
TI  - The effect of ammonium on assimilatory nitrate reduction in the haloarchaeon 
      Haloferax mediterranei.
PG  - 759-67
AB  - Physiology, regulation and biochemical aspects of the nitrogen assimilation are 
      well known in Prokarya or Eukarya but they are poorly described in Archaea 
      domain. The haloarchaeon Haloferax mediterranei can use different nitrogen 
      inorganic sources (NO (3) (-) , NO (2) (-) or NH (4) (+) ) for growth. Different 
      approaches were considered to study the effect of NH (4) (+) on nitrogen 
      assimilation in Hfx. mediterranei cells grown in KNO(3) medium. The NH (4) (+) 
      addition to KNO(3) medium caused a decrease of assimilatory nitrate (Nas) and 
      nitrite reductases (NiR) activities. Similar effects were observed when 
      nitrate-growing cells were transferred to NH (4) (+) media. Both activities 
      increased when NH (4) (+) was removed from culture, showing that the negative 
      effect of NH (4) (+) on this pathway is reversible. These results suggest that 
      ammonium causes the inhibition of the assimilatory nitrate pathway, while nitrate 
      exerts a positive effect. This pattern has been confirmed by RT-PCR. In the 
      presence of both NO (3) (-) and NH (4) (+) , NH (4) (+) was preferentially 
      consumed, but NO (3) (-) uptake was not completely inhibited by NH (4) (+) at 
      prolonged time scale. The addition of MSX to NH (4) (+) or NO (3) (-) cultures 
      results in an increase of Nas and NiR activities, suggesting that NH (4) (+) 
      assimilation, rather than NH (4) (+ ) per se, has a negative effect on 
      assimilatory nitrate reduction in Hfx. mediterranei.
FAU - Martinez-Espinosa, Rosa Maria
AU  - Martinez-Espinosa RM
AD  - Division de Bioquimica y Biologia Molecular, Facultad de Ciencias, Universidad de 
      Alicante, Ap. 99, 03080, Alicante, Spain. rosa.martinez@ua.es
FAU - Lledo, Belen
AU  - Lledo B
FAU - Marhuenda-Egea, Frutos C
AU  - Marhuenda-Egea FC
FAU - Bonete, Maria Jose
AU  - Bonete MJ
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20070616
PL  - Germany
TA  - Extremophiles
JT  - Extremophiles : life under extreme conditions
JID - 9706854
RN  - 0 (Archaeal Proteins)
RN  - 0 (Culture Media, Serum-Free)
RN  - 0 (Nitrates)
RN  - 0 (Nitrites)
RN  - 0 (Potassium Compounds)
RN  - 0 (Quaternary Ammonium Compounds)
RN  - 0 (RNA, Messenger)
RN  - 1982-67-8 (Methionine Sulfoximine)
RN  - EC 1.7.1.3 (Nitrate Reductase (NADPH))
RN  - EC 1.7.1.4 (Nitrite Reductase (NAD(P)H))
RN  - RU45X2JN0Z (potassium nitrate)
RN  - T8YA51M7Y6 (ammonium nitrate)
SB  - IM
MH  - Archaeal Proteins/*metabolism
MH  - Culture Media, Serum-Free/metabolism
MH  - Enzyme Induction
MH  - Gene Expression Regulation, Archaeal
MH  - Haloferax mediterranei/enzymology/growth & development/*metabolism
MH  - Methionine Sulfoximine/metabolism
MH  - Nitrate Reductase (NADPH)/biosynthesis/genetics/*metabolism
MH  - Nitrates/*metabolism
MH  - Nitrite Reductase (NAD(P)H)/biosynthesis/genetics/*metabolism
MH  - Nitrites/metabolism
MH  - *Nitrogen Fixation
MH  - Oxidation-Reduction
MH  - Potassium Compounds/metabolism
MH  - Quaternary Ammonium Compounds/*metabolism
MH  - RNA, Messenger/metabolism
MH  - Time Factors
EDAT- 2007/06/19 09:00
MHDA- 2008/03/28 09:00
CRDT- 2007/06/19 09:00
PHST- 2007/02/02 00:00 [received]
PHST- 2007/05/25 00:00 [accepted]
PHST- 2007/06/19 09:00 [pubmed]
PHST- 2008/03/28 09:00 [medline]
PHST- 2007/06/19 09:00 [entrez]
AID - 10.1007/s00792-007-0095-9 [doi]
PST - ppublish
SO  - Extremophiles. 2007 Nov;11(6):759-67. doi: 10.1007/s00792-007-0095-9. Epub 2007 
      Jun 16.