NTU Undergraduates' research April 2014 - Biosciences | Page 109

Characterisation of a dominant negative for human DNA polymerase gamma.

Nottingham Trent University.

Characterisation of a dominant negative for
human DNA polymerase gamma
Adam Owen
ABSTRACT
DNA Polymerase Gamma is the sole replicative enzyme of the mitochondrial genome that is responsible for
the upkeep of mitochondrial copy number and the repair of damaged or modified nucleotides. The POLG
protein has three main domains that are each responsible for separate processes affiliated with POLG,
modifications in any of the domains are known to causes severe human diseases and therefore the
characterisation of the modifications are vital. This paper focuses on the modification D890N located within
the polymerase domain of POLG and begins the process of characterising the effects of its expression
through the production of a dominant negative phenotype. The expression of the D890N POLG greatly
reduced the replicative properties of the wild-type POLG and caused vast mtDNA depletion within HEK293
cells. The depletion of the mtDNA was also linked to the large increase in production of lactate and
therefore loss of respiratory complexes. However, the effects of the removal of the D890N phenotype is still
unknown and would still need to be characterised to complete the model
Keywords: POLG, Mitochondria, D890N, Dominant Negative, Characterisation, mtDNA.

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