Viruses infecting marine picoplancton encode functional potassium ion channels

Area of Science:

• Virology
• Molecular Biology
• Biophysics

Background:

• Phycodnaviruses are double-stranded DNA viruses that infect algae.
• These viruses possess large genomes encoding diverse proteins, including potassium (K+) channels.
• K+ channels are crucial for cellular function and are found in prokaryotes and eukaryotes.

Purpose of the Study:

• To investigate novel K+ channel sequences identified in viruses from marine and Antarctic environments.
• To characterize the structure and function of these newly discovered viral K+ channels.

Main Methods:

• Bioinformatic screening of viral genomes for K+ channel homologs.
• Sequence analysis and structural prediction of identified K+ channel proteins.
• Electrophysiological studies to confirm channel function.

Main Results:

• Discovery of two genes encoding 78- and 79-amino acid proteins, representing the smallest known K+ channels.
• Identification of unusual sequences within the canonical alpha-helices of these viral K+ channels.
• Structural predictions showed conserved alpha-helix folds but lacked expected transmembrane domains.
• Electrophysiological data confirmed the functionality of these novel K+ channels.

Conclusions:

• Phycodnaviruses encode exceptionally small, functional K+ channels with unique structural features.
• These findings highlight the diversity of viral gene products and their potential roles in host-virus interactions.
• The study expands the known repertoire of viral ion channels and their biophysical properties.