Synuclein expression in the lizard Anolis carolinensis

The synuclein (syn) family comprises three proteins: alpha-, beta- and gamma-syns. In humans, they are involved in neurodegenerative diseases such as Parkinson's disease and in tumors. Members of the syn family were sequenced in representative species of all vertebrates and the comparative analysis of amino acid sequences suggests that syns are evolutionarily conserved, but information about their expression in vertebrate lineages is still scarce and completely lacking in reptiles. In this study, the expression of genes coding for alpha-, beta- and gamma-syns was analyzed in the green lizard Anolis carolinensis by semiquantitative RT-PCR and Western blot. Results demonstrate good expression levels of the three syns in the lizard nervous system, similarly to human syns. This, together with the high identity between lizard and human syns, suggests that these proteins fulfill evolutionarily conserved functions. However, differences between lizard and humans in the expression of syn variants (two different variants of gamma-syn were detected in A. carolinensis) and differences in some amino acids in key positions for the regulation of protein conformation and affinity for lipid and metal ions also suggest that these proteins may have acquired different functional specializations in the two lineages.