Dynamic expression of LIM cofactors in the developing mouse neural tube.
The developmental regulation of LIM homeodomain transcription factors (LIM-HD) by the LIM domain-binding cofactors CLIM/Ldb/NLI and RLIM has been demonstrated. Whereas CLIM cofactors are thought to be required for at least some of the in vivo functions of LIM-HD proteins, the ubiquitin ligase RLIM functions as a negative regulator by its ability to target CLIM cofactors for proteasomal degradation. In this report, we have investigated and compared the protein expression of both factors in the developing mouse neural tube. We co-localize both proteins in many tissues and, although widely expressed, we detect high levels of both cofactors in specific neural tube regions, e.g., in the ventral neural tube, where motor neurons reside. The mostly ubiquitous distribution of RLIM- and CLIM-encoding mRNA differs from the more specific expression of both cofactors at the protein level, indicating post-transcriptional regulation. Furthermore, we show that both cofactors not only co-localize with each other but also with Isl and Lhx3 LIM-HD proteins in developing ventral neural tube neurons. Our results demonstrate the dynamic expression of cofactors participating in the regulation of LIM-HD proteins during the development of the neural tube in mice and suggest additional post-transcriptional regulation in the nuclear LIM-HD protein network.
Ostendorff
Heather P
HP
Zentrum für Molekulare Neurobiologie Hamburg , Universität Hamburg, Martinistr. 85, 20251 Hamburg, Germany.
Tursun
Baris
B
Cornils
Kerstin
K
Schlüter
Anne
A
Drung
Alexander
A
Güngör
Cenap
C
Bach
Ingolf
I
D000818:Animals; D002490:Central Nervous System / Q000737:chemistry / Q000196:embryology*; D004268:DNA-Binding Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D018398:Homeodomain Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D060588:LIM Domain Proteins; D060850:LIM-Homeodomain Proteins; D008667:Metalloproteins / Q000032:analysis; D051379:Mice / Q000196:embryology* / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D012097:Repressor Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D044767:Ubiquitin-Protein Ligases
D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; C085115:Is1-1 protein; D060588:LIM Domain Proteins; D060850:LIM-Homeodomain Proteins; C102084:Ldb1 protein, mouse; C106649:Ldb2 protein, mouse; C499523:Lhx1 protein, mouse; D008667:Metalloproteins; D012333:RNA, Messenger; D012097:Repressor Proteins; D014157:Transcription Factors; C120758:Rlim protein, mouse; D044767:Ubiquitin-Protein Ligases