Source:http://linkedlifedata.com/resource/pubmed/id/12874135
Switch to
Predicate | Object |
---|---|
rdf:type | |
lifeskim:mentions | |
pubmed:issue |
17
|
pubmed:dateCreated |
2003-7-22
|
pubmed:abstractText |
The Xenopus LIM homeodomain (LIM-HD) protein, Xlim-1, is expressed in the Spemann organizer and cooperates with its positive regulator, Ldb1, to activate organizer gene expression. While this activation is presumably mediated through Xlim-1/Ldb1 tetramer formation, the mechanisms regulating proper Xlim-1/Ldb1 stoichiometry remains largely unknown. We isolated the Xenopus ortholog (XRnf12) of the RING finger protein Rnf12/RLIM and explored its functional interactions with Xlim-1 and Ldb1. Although XRnf12 functions as a E3 ubiquitin ligase for Ldb1 and causes proteasome-dependent degradation of Ldb1, we found that co-expression of a high level of Xlim-1 suppresses Ldb1 degradation by XRnf12. This suppression requires both the LIM domains of Xlim-1 and the LIM interaction domain of Ldb1, suggesting that Ldb1, when bound to Xlim-1, escapes degradation by XRnf12. We further show that a high level of Ldb1 suppresses the organizer activity of Xlim-1/Ldb1, suggesting that excess Ldb1 molecules disturb Xlim-1/Ldb1 stoichiometry. Consistent with this, Ldb1 overexpression in the dorsal marginal zone suppresses expression of several organizer genes including postulated Xlim-1 targets, and importantly, this suppression is rescued by co-expression of XRnf12. These data suggest that XRnf12 confers proper Ldb1 protein levels and Xlim-1/Ldb1 stoichiometry for their functions in the organizer. Together with the similarity in the expression pattern of Ldb1 and XRnf12 throughout early embryogenesis, we propose Rnf12/RLIM as a specific regulator of Ldb1 to ensure its proper interactions with LIM-HD proteins and possibly other Ldb1-interacting proteins in the organizer as well as in other tissues.
|
pubmed:language |
eng
|
pubmed:journal | |
pubmed:citationSubset |
IM
|
pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/DNA-Binding Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Homeodomain Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/LIM-Homeodomain Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Lhx1 protein, Xenopus,
http://linkedlifedata.com/resource/pubmed/chemical/Repressor Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Transcription Factors,
http://linkedlifedata.com/resource/pubmed/chemical/XLdb1 protein, Xenopus,
http://linkedlifedata.com/resource/pubmed/chemical/Xenopus Proteins
|
pubmed:status |
MEDLINE
|
pubmed:month |
Sep
|
pubmed:issn |
0950-1991
|
pubmed:author | |
pubmed:issnType |
Print
|
pubmed:volume |
130
|
pubmed:owner |
NLM
|
pubmed:authorsComplete |
Y
|
pubmed:pagination |
4161-75
|
pubmed:dateRevised |
2011-11-17
|
pubmed:meshHeading |
pubmed-meshheading:12874135-Amino Acid Sequence,
pubmed-meshheading:12874135-Animals,
pubmed-meshheading:12874135-DNA-Binding Proteins,
pubmed-meshheading:12874135-Gastrula,
pubmed-meshheading:12874135-Homeodomain Proteins,
pubmed-meshheading:12874135-LIM-Homeodomain Proteins,
pubmed-meshheading:12874135-Mesoderm,
pubmed-meshheading:12874135-Molecular Sequence Data,
pubmed-meshheading:12874135-Organizers, Embryonic,
pubmed-meshheading:12874135-Repressor Proteins,
pubmed-meshheading:12874135-Transcription Factors,
pubmed-meshheading:12874135-Xenopus,
pubmed-meshheading:12874135-Xenopus Proteins
|
pubmed:year |
2003
|
pubmed:articleTitle |
Selective degradation of excess Ldb1 by Rnf12/RLIM confers proper Ldb1 expression levels and Xlim-1/Ldb1 stoichiometry in Xenopus organizer functions.
|
pubmed:affiliation |
Department of Biological Sciences, Graduate School of Science, University of Tokyo, Tokyo 113-0033, Japan.
|
pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
|