Analysis of isoform expression of autophagy genes

Abstract

Autophagy is a catabolic process present in all eukaryotic cells. It is necessary for maintaining cellular homeostasis and the overall viability of mammals.In the center of the human autophagy pathway are ubiquitin like modifier proteins belonging to the LC3/GABARAP gene family. These proteins are necessary for normal autophagic function.In this study we compare the expression ratios of 3 separate GABARAP isoforms: GABARAP(1), GABARAP(3) and GABARAP(5). The GABARAP protein is encoded by one of 7 human LC3/GABARAP genes.An expression analysis shows an unexpected ratio of GABARAP isoform transcripts. The GABARAP(1) transcript which encodes the full-length protein is the least expressed as compared to GABARAP(3) and GABARAP(5). Surprisingly, GABARAP(3) andGABARAP(5) are missing their N- and C-termini, respectively, both of which are necessary for the normal autophagic function of GABARAP.Along with the expression analysis, a plasmid encoding GABARAP(1) was generated and overexpressed in a human cell line.