Linked Life Data

14767769

Source:http://linkedlifedata.com/resource/pubmed/id/14767769

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2004-5-5
pubmed:abstractText
In wild-type Nicotiana plumbaginifolia Viv. and other higher plants, nitrate reductase (NR) is regulated at the post-translational level and is rapidly inactivated in response to, for example, a light-to-dark transition. This inactivation is caused by phosphorylation of a conserved regulatory serine residue, Ser 521 in tobacco, and interaction with divalent cations or polyamines, and 14-3-3 proteins. The physiological importance of the post-translational NR modulation is presently under investigation using a transgenic N. plumbaginifolia line. This line expresses a mutated tobacco NR where Ser 521 has been changed into aspartic acid (Asp) by site-directed mutagenesis, resulting in a permanently active NR enzyme. When cut leaves or roots of this line (S(521)) were placed in darkness in a buffer containing 50 mM KNO(3), nitrite was excreted from the tissue at rates of 0.08-0.2 micromol (g FW)(-1) h(-1) for at least 5 h. For the control transgenic plant (C1), which had the regulatory serine of NR intact, nitrite excretion was low and halted completely after 1-3 h. Without nitrate in the buffer in which the tissue was immersed, nitrite excretion was also low for S(521), although 20-40 micromol (g FW)(-1) nitrate was present inside the tissue. Apparently, stored nitrate was not readily available for reduction in darkness. Leaf tissue and root segments of S(521) also emitted much more nitric oxide (NO) than the control. Importantly, NO emission from leaf tissue of S(521) was higher in the dark than in the light, opposite to what was usually observed when post-translational NR modulation was operating.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0032-0935
pubmed:author
pubmed:issnType
Print
pubmed:volume
219
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
59-65
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Mutation of the regulatory phosphorylation site of tobacco nitrate reductase results in high nitrite excretion and NO emission from leaf and root tissue.
pubmed:affiliation
School of Technology and Science, Stavanger University College, Box 8002 Ullandhaug, 4068 Stavanger, Norway.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't