silencing of mutant ar co- activators as a therapeutic ......silencing of mutant ar co-activators as...
TRANSCRIPT
Silencing of Mutant AR Co-activators as a Therapeutic
Approach
Manuela Basso, Assistant ProfessorUniversity of Trento, Centre for
Integrative Biology
Italian Meeting with researchers and Scientists
November 12th 2016, MilanApril 18th 2015, TrentoNovember 2013, Padova
The fourth meeting is coming soon….
Neuron and muscle
degeneration
QQQQQQQCAGCAGCAGCAGCAGCAG…
>36 repeats
HD Mutant ARAR gene
SBMA is caused by expansion of a polyglutamine tract in AR
Chr X
p q
AR gene
CAGCAGCAG…
8-29 repeats
WT QQQQ ARAR gene
Healthy neuron and muscle
AR post-translational modifications
Polyglutamine tract
Phosphorylation
Acetylation
SUMOylation
Palazzolo et al., 2007Scaramuzzino et al., 2015
Montie et al., 2012Chua et al., 2015
S96
R2
10
S21
5
S79
2
1 920555 670
AR
R methylation
R7
89
R7
87
R2
12
Qn DBD LBDNTD
K6
30
K6
32
K6
33
S38
5
S51
8
Arginine methylation is catalyzed by Protein Arginine Methyltransferases (PRMTs)
PRMT1 PRMT2 PRMT3 PRMT4 PRMT6PRMT8
Type IPRMTs
PRMT5 PRMT9
Type IIPRMTs
PRMT7
Type IIIPRMT
Basso and Pennuto, 2015
Basso & Pennuto, Exp Neurol 2015
Arginine methylation and serine phosphorylation are mutually exclusive and both modulate AR function
Does PRMT6 modify toxicity in vivo?
In collaboration with the lab of Udai Pandey, University of Pittsburgh
AR X KD PRMT6
UAS-AR0Qor
UAS-AR52Q
GMR-Gal4; DART8 silencing
AR is transcription factor
https://en.wikipedia.org/wiki/Androgen_receptor#/media/File:Human_androgen_receptor_and_androgen_binding.svg
PRM
T66
????
PRMT6 specifically transactivates AR
Scaramuzzino et al., Neuron 2015
AR transactivation by PRMT6 is enhanced by polyglutamine expansion
3.3-fold
5.3-foldARE Luc
AR
Testosterone
SBMA pathogenesis is modified through arginine methylation of polyQ-expanded AR
Silence PRMT6 by novel selective inhibitors to assess the rescue of polyQ-expanded AR
2
Silence PRMT6 by an artificial microRNA to assess the rescue of polyQ-expanded AR in vivo
1
Hypothesis
The artificial miRNA 13.1 reduces AR functionFo
ld c
han
ge (
ove
r n
ega
tive
co
ntr
ol)
Fold
ch
ange
(o
ver
ne
gati
ve c
on
tro
l)
Chivet et al., in preparation
Weight body and strength are reduced in mice overexpressing expanded AR
In progress:
Artificial miRNA for PRMT6
Behavior assessment
In collaboration with Giuseppe Ronzitti, Genethon
2
PRMTs
SAM /AdoMet
Me
Adox / MTA
Novel pharmacological inhibitorsMS023 and MS049
In collaboration with Masoud Vedadi, University of Toronto
1-Which are other AR coactivators?
2-Is it feasible to reduce the over-activation of AR to correct its transcriptional activity but maintain its physiological functions?
Where are we going?
Maria Pennuto’s LabUniversity of Padova
Mathilde Chivet (Postdoctoral fellow)Carlo Rinaldi’s LabOxford University
Acknowledgements
Alice Migazzi, PhD student Mathi Chivet, postdoc
Debasmita Tripathy, postdoc
Giuseppe RonzittiGenethon, France