bi9b00749_si_001.pdf (437.31 kB)
Disease-Associated Mutations G589A and V590F Relieve Replication Focus Targeting Sequence-Mediated Autoinhibition of DNA Methyltransferase 1
journal contribution
posted on 2019-12-13, 21:29 authored by Emma K. Dolen, James H. McGinnis, Rachel N. Tavory, Jill A. Weiss, Rebecca L. SwitzerIn eukaryotes, the most common epigenetic DNA modification
is methylation
of carbon 5 of cytosines, predominantly in CpG dinucleotides. Methylation
patterns are established and maintained by a family of proteins known
as DNA methyltransferases (DNMTs). DNA methylation is an important
epigenetic mark associated with gene repression, and disruption of
the normal DNA methylation pattern is known to play a role in several
disease states. Methylation patterns are primarily maintained by DNMT1,
which possesses specificity for methylation of hemimethylated DNA.
DNMT1 is a multidomain protein with a C-terminal catalytic methyltransferase
domain and a large N-terminal regulatory region. The replication focus
targeting sequence (RFTS) domain, found in the regulatory region,
is an endogenous inhibitor of DNMT1 activity. Recently, several mutations
in the RFTS domain were shown to be causal for two adult onset neurodegenerative
diseases; however, little is known about the impact of these mutations
on the structure and function of DNMT1. Two of these mutations, G589A
and V590F, are associated with development of autosomal dominant cerebellar
ataxia, deafness, and narcolepsy (ADCA-DN). We have successfully expressed
and purified G589A and V590F DNMT1 for in vitro studies.
The mutations significantly decrease the thermal stability of DNMT1,
yet the mutant proteins exhibit 2.5–3.5-fold increases in DNA
binding affinity. In addition, the mutations weaken RFTS-mediated
inhibition of DNA methylation activity. Taken together, these data
suggest these disease-associated mutations decrease protein stability
and, at least partially, relieve normal RFTS-mediated autoinhibition
of DNMT1.
History
Usage metrics
Categories
Keywords
DNMT 1 activityDNA Methyltransferase 1ADCA-DNRFTSDisease-Associated Mutations G 589ADNA methylation activityadult onset neurodegenerative diseasesG 589AMethylation patternsDNA methylation patternV 590F DNMT 1disease-associated mutations decrease protein stabilityV 590F Relieve Replication Focus Targeting Sequence-Mediated AutoinhibitionDNA binding affinity
Licence
Exports
RefWorks
BibTeX
Ref. manager
Endnote
DataCite
NLM
DC