Abstract
Establishment of presynaptic mechanisms by proteins that regulate neurotransmitter release in the presynaptic
active zone
is considered a fundamental step in animal evolution. Rab3 interacting molecule-binding proteins (Rimbps) are crucial components of the presynaptic
active zone
and key players in calcium homeostasis. Although
Rimbp
involvement in these dynamics has been described in distantly related models such as fly and human, the role of this family in most invertebrates remains obscure. To fill this gap, we defined the evolutionary history of
Rimbp
family in animals, from sponges to mammals. We report, for the first time, the expression of the two isoforms of the unique
Rimbp
family member in
Ciona robusta
in distinct domains of the larval nervous system. We identify intronic enhancers that are able to drive expression in different nervous system territories partially corresponding to
Rimbp
endogenous expression. The analysis of gene expression patterns and the identification of regulatory elements of
Rimbp
will positively impact our understanding of this family of genes in the context of
Ciona
embryogenesis.