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Journal of Glycobiology | ISSN: 2168-958X | Volume 7
Glycobiology & Glycoproteomics
5
th
International Conference on
&
August 27-28, 2018 | Toronto, Canada
Molecular Biology & Nucleic Acids
3
rd
International Conference on
Lysine acetylation of nuclear Pif1 alters its enzymatic function
Onyekachi E Ononye, Christopher W Sausen, Matthew L Bochman,
and
Lata Balakrishnan
Indiana University Purdue University Indianapolis, IN
P
etite integration frequency 1 (Pif1) is a 5’-3’ helicase that is implicated in the maintenance of the fidelity of nuclear and
mitochondrial DNA. The protein’s preference for unwinding RNA-DNA hybrids makes it a key player during various
DNA transactions in the cell such as DNA replication, repair, and telomere maintenance, where such substrates are abundant.
We recently discovered Pif1 was post-translationally modified by lysine acetylation both in mammalian and
Saccharomyces
cerevisiae
cells. The current focus of our work is to define the role of lysine acetylation in modulating the enzymatic properties
of the Pif1. Genetic knockouts of the dynamic modifiers of lysine acetylation have implicated specific lysine acetyltransferases
and deacetylases in the dynamic modification of Pif1. Using purified recombinant yeast acetyltransferases to in vitro acetylate
full-length recombinant Pif1 protein, we tested the alterations in the enzymatic activities of acetylated Pif1 protein compared to
the unmodified form. From the electromobility gel shift assays (EMSA) and biolayer interferometry (BLITZ) analysis, we found
that the acetylated form of Pif1 had higher binding affinity compared to the unmodified form. Directly correlating to increased
substrate binding, the acetylated form of Pif1 also showed significantly higher helicase and ATPase activity. Additionally,
using mass spectrometry, we have mapped out the sites of lysine acetylation of both in vivo and in vitro acetylated Pif1. We are
currently in the process of understanding specific cellular triggers of Pif1 acetylation and also the impact of lysine acetylation
of Pif1 on genetic stability.
Biography
Onyekachi Ononye is a graduate student in Dr Balakrishnan’s laboratory at Indiana University-Purdue University Indianapolis. Her research focus explores the
role of lysine acetylation in modulating DNA replication proteins on the lagging strand. Using a plethora of biochemistry techniques, Onyekachi is working towards
defining one of the regulatory pathways required for high fidelity processing of DNA.
oononye@iu.eduOnyekachi E Ononye et al., J Glycobiol 2018, Volume 7
DOI: 10.4172/2168-958X-C1-012