BTB
(bric-a-brack,
Tramtrack,
and
broad
complex)
is
a
diverse
group
of
protein-protein
interaction
domains
found
within
metazoan
proteins.
Transcription
factors
contain
dimerizing
subtype
with
characteristic
N-terminal
extension.
The
Tramtrack
(TTK)
distinct
type
domain,
which
can
multimerize.
Single-particle
cryo-EM
microscopy
revealed
that
the
TTK-type
assemble
into
hexameric
structure
consisting
three
canonical
dimers
connected
through
previously
uncharacterized
interface.
We
demonstrated
are
only
in
Arthropods
have
undergone
lineage-specific
expansion
modern
insects.
Drosophila
genome
encodes
24
transcription
domains,
whereas
four
non-TTK-type
domains.
Yeast
two-hybrid
analysis
an
unusually
potential
for
heteromeric
associations
presumably
dimer-dimer
Thus,
structurally
functionally
protein
specific
to
Arthropodan
factors.
Nature,
Journal Year:
2023,
Volume and Issue:
623(7985), P. 175 - 182
Published: Sept. 28, 2023
The
Anopheles
mosquito
is
one
of
thousands
species
in
which
sex
differences
play
a
central
part
their
biology,
as
only
females
need
blood
meal
to
produce
eggs.
Sex
differentiation
regulated
by
chromosomes,
but
presence
creates
dosage
imbalance
between
males
(XY)
and
(XX).
Dosage
compensation
(DC)
can
re-equilibrate
the
expression
chromosomal
genes.
However,
because
DC
mechanisms
have
been
fully
characterized
few
model
organisms,
key
questions
about
its
evolutionary
diversity
functional
necessity
remain
unresolved1.
Here
we
report
discovery
previously
uncharacterized
gene
(sex
chromosome
activation
(SOA))
master
regulator
malaria
gambiae.
Sex-specific
alternative
splicing
prevents
SOA
protein
females.
male
isoform
encodes
DNA-binding
that
binds
promoters
active
X
Expressing
sufficient
induce
female
cells.
Male
mosquitoes
lacking
or
ectopically
expressing
exhibit
misregulation,
compatible
with
viability
causes
developmental
delay.
Thus,
our
molecular
analyses
non-model
organism
elucidates
steps
lead
establishment
chromosome-specific
fine-tuning
mechanism.
Critical Reviews in Biochemistry and Molecular Biology,
Journal Year:
2024,
Volume and Issue:
59(3-4), P. 139 - 153
Published: May 22, 2024
Chromatin
is
densely
packed
with
nucleosomes,
which
limits
the
accessibility
of
many
chromatin-associated
proteins.
Pioneer
factors
(PFs)
are
usually
viewed
as
a
special
group
sequence-specific
transcription
(TFs)
that
can
recognize
nucleosome-embedded
motifs,
invade
compact
chromatin,
and
generate
open
chromatin
regions.
Through
this
process,
PFs
initiate
cascade
events
play
key
roles
in
gene
regulation
cell
differentiation.
A
current
debate
field
if
belong
to
unique
subset
TFs
intrinsic
"pioneering
activity",
or
all
have
potential
function
within
certain
cellular
contexts.
There
also
different
views
regarding
feature(s)
define
pioneering
activity.
In
review,
we
present
evidence
from
literature
related
these
alternative
discuss
how
potentially
reconcile
them.
It
possible
both
properties,
like
tight
nucleosome
binding
structural
compatibility,
conditions,
concentration
co-factor
availability,
important
for
PF
function.
BTB
(bric-a-brack,
Tramtrack,
and
broad
complex)
is
a
diverse
group
of
protein-protein
interaction
domains
found
within
metazoan
proteins.
Transcription
factors
contain
dimerizing
subtype
with
characteristic
N-terminal
extension.
The
Tramtrack
(TTK)
distinct
type
domain,
which
can
multimerize.
Single-particle
cryo-EM
microscopy
revealed
that
the
TTK-type
assemble
into
hexameric
structure
consisting
three
canonical
dimers
connected
through
previously
uncharacterized
interface.
We
demonstrated
are
only
in
Arthropods
have
undergone
lineage-specific
expansion
modern
insects.
Drosophila
genome
encodes
24
transcription
domains,
whereas
four
non-TTK-type
domains.
Yeast
two-hybrid
analysis
an
unusually
potential
for
heteromeric
associations
presumably
dimer-dimer
Thus,
structurally
functionally
protein
specific
to
Arthropodan
factors.
