PubMed Journals: J Mol Biol
Source: PMID: 12787665
⇦ ⇨ J Mol Biol. 2003 Jun 13;329(4):631-44.
Functional domains of FOXJ2.
Gómez-Ferrería MA(1), Rey-Campos J.
(1) Departamento de Biología Celular y Desarrollo,
Centro de Investigaciones Biológicas, Consejo
Superior de Investigaciones Científicas
(CSIC), Velázquez 144, 28006, Madrid, Spain.
FOXJ2 is a fork head transcriptional activator,
the expression of which starts very early
in embryonic development and it is distributed
widely in the adult. Here, we describe the
characterization of domains that are important
for its function. FOXJ2 is localized constitutively
at the nucleus of the cell. Two tyrosine
residues and a stretch of basic amino acid
residues at the N and C-terminal ends of the
fork head domain, respectively, are important
for its nuclear targeting. These residues
are conserved strongly among all members
of the fork head family, suggesting that
they could be involved in the nuclear translocation
mechanism of all fork head factors. In addition
to the AB domain, we have found, at least,
two other transactivation domains: Domain
I, at the N terminus, and the H/P domain,
rich in histidine and proline residues.
Although the AB domain shows the strongest
transactivation capacity, all three domains
are required for full FOXJ2 transcriptional
activity. Furthermore, a fourth region rich
in proline and glutamine residues and with
no intrinsic transactivation function, the
P/Q domain, appears to play an important
role in the FOXJ2-mediated transactivation
mechanism. Although FOXJ2 can be phosphorylated
in two serine residues, this post-translational
modification did not appear to be essential
for transactivation. Finally, we have found
that the W2 wing of the fork head domain
of FOXJ2 is dispensable for specific DNA
binding, although it could have a weak stabilizing
role for the DNA-FOXJ2 complex.
PMID: 12787665 [Indexed for MEDLINE]