RT Journal
A1 Montesinos, Marı́a  Luz
A1 Foucher, Isabelle
A1 Conradt, Marcus
A1 Mainguy, Gaëll
A1 Robel, Laurence
A1 Prochiantz, Alain
A1 Volovitch, Michel
T1 The Neuronal Microtubule-Associated Protein 1BIs under Homeoprotein Transcriptional Control
JF The Journal of Neuroscience 
JO The Journal of Neuroscience 
YR 2001 
FD May 15 
VO 21 
IS 10 
SP 3350 
OP 3359 
DO 10.1523/JNEUROSCI.21-10-03350.2001 
UL http://www.jneurosci.org/content/21/10/3350.abstract 
AB To identify genes regulated by homeoprotein transcription factors in postnatal neurons, the DNA-binding domain (homeodomain) of Engrailed homeoprotein was internalized into rat cerebellum neurons. The internalized homeodomain (EnHD) acts as a competitive inhibitor of Engrailed and of several homeoproteins (Mainguy et al., 2000). Analysis by differential display revealed thatmicrotubule-associated protein 1B (MAP1B) mRNA is upregulated by EnHD. This upregulation does not require protein synthesis, suggesting a direct effect of the homeodomain onMAP1B transcription. The promoter region of MAP1Bwas cut into several subdomains, and each subdomain was tested for its ability to bind Engrailed and EnHD and to associate with Engrailed-containing cerebellum nuclear extracts. In addition, the activity, and regulation by Engrailed, of each subdomain and of the entire promoter were evaluated in vivo by electroporation in the chick embryo neural tube. These experiments demonstrate that MAP1B promoter is regulated by Engrailedin vivo. Moreover, they show that one promoter domain that contains all ATTA homeoprotein cognate binding sites common to the rat and human genes is an essential element of this regulation. It is thus proposed that MAP1B, a cytoskeleton protein involved in neuronal growth and regeneration, is under homeoprotein transcriptional regulation.