TDP-43 regulates its mRNA levels through a negative feedback loop.
TAR DNA-binding protein (TDP-43) is an evolutionarily conserved heterogeneous nuclear ribonucleoprotein (hnRNP) involved in RNA processing, whose abnormal cellular distribution and post-translational modification are key markers of certain neurodegenerative diseases, such as amyotrophic lateral sclerosis and frontotemporal lobar degeneration. We generated human cell lines expressing tagged forms of wild-type and mutant TDP-43 and observed that TDP-43 controls its own expression through a negative feedback loop. The RNA-binding properties of TDP-43 are essential for the autoregulatory activity through binding to 3' UTR sequences in its own mRNA. Our analysis indicated that the C-terminal region of TDP-43, which mediates TDP-43-hnRNP interactions, is also required for self-regulation. TDP-43 binding to its 3' UTR does not significantly change the pre-mRNA splicing pattern but promotes RNA instability. Moreover, blocking exosome-mediated degradation partially recovers TDP-43 levels. Our findings demonstrate that cellular TDP-43 levels are under tight control and it is likely that disease-associated TDP-43 aggregates disrupt TDP-43 self-regulation, thus contributing to pathogenesis.
Department of Molecular Pathology, International Centre for Genetic Engineering and Biotechnology, Trieste, Italy.
Youhna M
YM
Ayala
Laura
L
De Conti
S Eréndira
SE
Avendaño-Vázquez
Ashish
A
Dhir
Maurizio
M
Romano
Andrea
A
D'Ambrogio
James
J
Tollervey
Jernej
J
Ule
Marco
M
Baralle
Emanuele
E
Buratti
Francisco E
FE
Baralle
D001483:Base Sequence; D015152:Blotting, Northern; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D025461:Feedback, Physiological / Q000502:physiology*; D005786:Gene Expression Regulation / Q000235:genetics*; D015723:Gene Library; D006801:Humans; D015151:Immunoblotting; D047468:Immunoprecipitation; D008969:Molecular Sequence Data; D010957:Plasmids / Q000235:genetics; D016133:Polymerase Chain Reaction; D034622:RNA Interference; D012323:RNA Processing, Post-Transcriptional / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism*; D017422:Sequence Analysis, DNA
D004268:DNA-Binding Proteins; D012333:RNA, Messenger