Hello, kitty: could cat allergy be a form of intoxication?

BACKGROUND

The relationship between slow loris ( spp.) venom (BGE protein) and the major cat allergen (Fel d 1) from domestic cat () is known for about two decades. Along this time, evidence was accumulated regarding convergences between them, including their almost identical mode of action.

METHODS

Large-scale database mining for Fel d 1 and BGE proteins in Felidae and spp., alignment, phylogeny proposition and molecular modelling, associated with directed literature review were assessed.

RESULTS

Fel d 1 sequences for 28 non-domestic felids were identified, along with two additional loris BGE protein sequences. Dimer interfaces are less conserved among sequences, and the chain 1 shows more sequence similarity than chain 2. Post-translational modification similarities are highly probable.

CONCLUSIONS

Fel d 1 functions beyond allergy are discussed, considering the great conservation of felid orthologs of this protein. Reasons for toxicity being found only in domestic cats are proposed in the context of domestication. The combination of the literature review, genome-derived sequence data, and comparisons with the venomous primate slow loris may point to domestic cats as potentially poisonous mammals.