The dual-coding gene SLC35A4 protects against oxidative stress

Area of Science:

• Molecular Biology
• Cell Biology
• Genetics

Background:

• Alternative proteins (AltProts) are biologically active proteins encoded from alternative open reading frames (AltORFs) within annotated genes.
• The SLC35A4 gene encodes both a reference protein (SLC35A4) and an alternative protein (AltSLC35A4).
• Previous research indicated increased translational efficiency of SLC35A4 during oxidative stress.

Purpose of the Study:

• To investigate the localization and function of AltSLC35A4.
• To confirm the translational regulation of SLC35A4 and AltSLC35A4 under oxidative stress.
• To determine the role of SLC35A4 and AltSLC35A4 in cellular resistance to oxidative stress.

Main Methods:

• Microscopy and biochemical analyses to determine protein localization.
• Ribosome profiling and Western blotting to assess protein expression and translational efficiency.
• Gene knockout studies to evaluate the impact on oxidative stress sensitivity.

Main Results:

• AltSLC35A4 was localized to the inner mitochondrial membrane.
• Oxidative stress induced translational upregulation of SLC35A4, but not AltSLC35A4.
• Knockout of SLC35A4 or AltSLC35A4 increased sensitivity to oxidative stress.

Conclusions:

• The dual-coding nature of SLC35A4 is functionally significant for oxidative stress resistance.
• AltProts encoded by AltORFs are important for eukaryotic gene function and cellular adaptation.
• This study resolves conflicting reports on AltSLC35A4 localization and establishes its role in stress response.