Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2005-7-27
pubmed:abstractText
Phytochrome A (phyA) plays a primary role in initiating seedling de-etiolation and is the only plant photoreceptor known to be activated by far-red light (FR). The signaling intermediate FHY1 appears to either participate directly in relaying the phyA signal or to positively regulate a critical signaling event(s) downstream of phyA activation. Here we identify a homolog of FHY1 named FHL (FHY1-like) as a novel signaling factor essential for complete responsiveness to phyA. FHL possesses functional nuclear localization and nuclear export signals. Lines in which FHL function was abolished by insertional mutagenesis or attenuated by RNAi-mediated suppression displayed a weaker hyposensitivity to continuous FR than fhy1 null mutants and most reported phyA signaling mutants. However, hypocotyl elongation assays indicated that suppression of FHL expression in fhy1-3 caused an insensitivity of hypocotyl elongation to FR and blue light (B) indistinguishable from that seen in phyA. Real-time PCR indicates that in FR, FHY1 transcripts are approximately 15-fold more abundant than FHL transcripts. Although both FHY1 and FHL are capable of homo- and hetero-interaction via their C-termini, the ability of FHL overexpression to restore wild-type (WT) morphological and molecular phenotypes to fhy1-3 seedlings suggests that the extreme insensitivity to FR associated with suppression of FHL expression in fhy1-3 cannot be accounted for by a critical role for FHY1-FHL heterodimers in phyA signal transmission. Rather, we suggest that the relative abundances of FHY1 and FHL in WT plants account for the differences in the severity of fhy1 and fhl mutations. As for FHY1, FHL transcript accumulation is dependent on FHY3 and is decreased after exposure to FR, R or B light. These findings reiterate the prevalence of partial degeneracy in plant signaling networks that regulate responses crucial to survival.
pubmed:grant
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/16045472-10444599, http://linkedlifedata.com/resource/pubmed/commentcorrection/16045472-10652141, http://linkedlifedata.com/resource/pubmed/commentcorrection/16045472-10817761, http://linkedlifedata.com/resource/pubmed/commentcorrection/16045472-10995393, http://linkedlifedata.com/resource/pubmed/commentcorrection/16045472-11449056, http://linkedlifedata.com/resource/pubmed/commentcorrection/16045472-11711433, http://linkedlifedata.com/resource/pubmed/commentcorrection/16045472-11726703, http://linkedlifedata.com/resource/pubmed/commentcorrection/16045472-11889039, http://linkedlifedata.com/resource/pubmed/commentcorrection/16045472-12023303, http://linkedlifedata.com/resource/pubmed/commentcorrection/16045472-12644683, http://linkedlifedata.com/resource/pubmed/commentcorrection/16045472-12711229, http://linkedlifedata.com/resource/pubmed/commentcorrection/16045472-12753585, http://linkedlifedata.com/resource/pubmed/commentcorrection/16045472-14645728, http://linkedlifedata.com/resource/pubmed/commentcorrection/16045472-15031264, http://linkedlifedata.com/resource/pubmed/commentcorrection/16045472-15078338, http://linkedlifedata.com/resource/pubmed/commentcorrection/16045472-15469493, http://linkedlifedata.com/resource/pubmed/commentcorrection/16045472-15741320, http://linkedlifedata.com/resource/pubmed/commentcorrection/16045472-1841723, http://linkedlifedata.com/resource/pubmed/commentcorrection/16045472-8364355, http://linkedlifedata.com/resource/pubmed/commentcorrection/16045472-8624438, http://linkedlifedata.com/resource/pubmed/commentcorrection/16045472-9482948, http://linkedlifedata.com/resource/pubmed/commentcorrection/16045472-9881160
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0960-7412
pubmed:author
pubmed:issnType
Print
pubmed:volume
43
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
356-70
pubmed:dateRevised
2011-4-21
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
FHL is required for full phytochrome A signaling and shares overlapping functions with FHY1.
pubmed:affiliation
Laboratory of Plant Molecular Biology, The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, N.I.H., Extramural