Date of this Version
Murry, C. 2020. Genetic Diversity of Potassium Ion Channel Proteins Encoded by Chloroviruses that Infect Chlorella heliozoae. Undergraduate Honors Thesis. University of Nebraska- Lincoln.
Chloroviruses are large, plaque-forming, double-stranded DNA viruses that infect chlorella-like green algae that live in a symbiotic relationship with protists. Chloroviruses have a genome from 290 to 370 kb, and they encode as many as 400 proteins. One interesting feature of chloroviruses is that they encode a potassium ion (K+) channel protein named Kcv. K+ channels are essential proteins for life. They cross the membrane of the cell to quickly and selectively allow K+ in or out of the cell. This helps regulate the electrical charge of a cell which in turn helps control electrical signaling in the cell. Potassium ion channels encoded by chlorovirus ATCV-1 that infect Chlorella heliozoae (SAG) is one of the smallest known functional potassium ion channel proteins consisting of 82 amino acids. The ATCV-1 virus Kcv gene has similarities to the family of two transmembrane domain K+ channel proteins: consisting of 2 transmembrane domains with a pore region in the middle making it an ideal model for studying K+ channels. Ninety Kcv genes from geographically distinct SAG viruses were sequenced to assess their genetic diversity. Of the 90 Kcv genes, there were 35 unique DNA sequences that translated into 26 unique amino acid sequences. The most conserved region of the Kcv protein was the filter, the turret and the pore helix were fairly conserved, and the outer and the inner helices of the Kcv protein, which are the transmembrane components, showed the most variability.