Siamese Cat Tyrosinase has Enhanced Proteasome Degradation and Increased Cellular Aggregation

Abstract

Aim: Siamese cats are a notable example of a temperature-sensitive partial albinism phenotype. The signature color-pointing pattern is the result of an amino acid substitution - G302R - in the cysteine-rich domain of feline tyrosinase. The precise mechanism for the loss of tyrosinase enzyme activity due to this mutation is unknown. Objective: We have used a cellular biology approach to unraveling the relationships between feline coloration, behavior and increased risk for feline cognitive dysfunction syndrome. GFP-fusion constructs of wild type domestic short hair tyrosinase and Siamese (G302R) tyrosinase were generated to study cellular trafficking, degradation and the propensity for cellular aggregation. Data Description: C-terminal GFP G302R expression has reduced Golgi localization, increased cytosolic fractions with reduced calnexin co-localization. N-terminal GFP constructs were retained in the ER, with little to no Golgi associated forms. C-terminal and N-terminal GFP G302R TYR is observed to have increased high molecular weight aggregation following proteasome inhibition.