Molecular characterization of the AdeI mutant of Chinese hamster ovary cells: A cellular model of adenylosuccinate lyase deficiency
Abstract
Adenylosuccinate lyase carries out two non-sequential steps in de novo AMP synthesis. Mutations in ADSL lead to an inborn error of metabolism originally characterized by developmental delay.
There is no effective treatment for ADSL deficiency. One important approach to understand ADSL deficiency is to develop cell culture models that allow investigation of the properties of ADSL mutants and the consequences of ADSL deficiency at the cellular level.
We previously reported the isolation and initial characterization of mutants of Chinese hamster ovary (CHO-K1) cells (AdeI) that lack detectable ADSL activity, accumulate ADSL substrates, and require adenine for growth. Here we report the cDNA sequences of ADSL from CHO-K1 and AdeI cells and describe a mutation resulting in an alanine to valine amino acid substitution at position 291 (A291V) in AdeI ADSL.
This substitution lies in the “signature sequence” of ADSL, inactivates the enzyme, and validates AdeI as a cellular model of ADSL deficiency.