Linked Life Data

2753895

Source:http://linkedlifedata.com/resource/pubmed/id/2753895

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
22
pubmed:dateCreated
1989-9-7
pubmed:abstractText
Avena seedlings grown in the presence of the plant tetrapyrrole synthesis inhibitor 4-amino-5-hexynoic acid contain less than 10% of the spectrally detectable phytochrome levels found in untreated seedlings, but continue to accumulate phytochrome apoprotein (Elich, T. D., and Lagarias, J. C. (1988) Plant Physiol. 88, 747-751). Using such tetrapyrrole-deficient seedlings, we have previously reported that phycocyanobilin, the cleaved prosthetic group of C-phycocyanin, can be incorporated into phytochrome in vivo to yield spectrally active holoprotein (Elich, T. D., McDonagh, A. F., Palma, L. A., and Lagarias, J. C. (1988) J. Biol. Chem. 264, 183-189). Here we show that addition of phycocyanobilin to soluble extracts of inhibitor-treated seedlings results in a rapid increase in spectrally active phytochrome holoprotein. The newly formed photoactive species displays a blue-shifted absorbance difference spectrum similar to that observed in the previous in vivo studies. The increase in spectral activity is consistent with conversion of all of the preexisting phytochrome apoprotein to functionally active holoprotein. The formation of a covalent phycocyanobilin-apophytochrome adduct is shown by an increase in Zn2+-dependent bilin fluorescence of the phytochrome polypeptide. A photoreversible, covalent adduct with a similar optical spectrum also forms when immunopurified apophytochrome is incubated with phycocyanobilin. ATP, reduced pyridine nucleotides, or other cofactors are not required for adduct formation. When biliverdin IX alpha is substituted for phycocyanobilin, no spectrally active covalent adduct is produced. These results indicate that an A-ring ethylidene-containing bilatriene is required for post-translational covalent attachment of bilin to apophytochrome and that apophytochrome may be the bilin C-S lyase which catalyzes bilin attachment.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Acyl Carrier Protein, http://linkedlifedata.com/resource/pubmed/chemical/Aminocaproic Acids, http://linkedlifedata.com/resource/pubmed/chemical/Apoproteins, http://linkedlifedata.com/resource/pubmed/chemical/Escherichia coli Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Fatty Acid Synthetase Complex..., http://linkedlifedata.com/resource/pubmed/chemical/Phycobilins, http://linkedlifedata.com/resource/pubmed/chemical/Phycocyanin, http://linkedlifedata.com/resource/pubmed/chemical/Phytochrome, http://linkedlifedata.com/resource/pubmed/chemical/Pigments, Biological, http://linkedlifedata.com/resource/pubmed/chemical/Plant Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Pyrroles, http://linkedlifedata.com/resource/pubmed/chemical/Tetrapyrroles, http://linkedlifedata.com/resource/pubmed/chemical/Vigabatrin, http://linkedlifedata.com/resource/pubmed/chemical/acpP protein, E coli, http://linkedlifedata.com/resource/pubmed/chemical/phycocyanobilin
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
264
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
12902-8
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Formation of a photoreversible phycocyanobilin-apophytochrome adduct in vitro.
pubmed:affiliation
Department of Biochemistry and Biophysics, University of California, Davis 95616.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S.