Characterization and role ofHelixcontactin‐related proteins in culturedHelix pomatianeurons

Abstract

We report on the structural and functional properties of the Helix contactin-related proteins (HCRPs), a family of closely related glycoproteins previously identified in the nervous system of the land snail Helix pomatia through antibodies against the mouse F3/contactin glycoprotein. We focus on HCRP1 and HCRP2, soluble FNIII domains-containing proteins of 90 and 45 kD bearing consensus motifs for both N- and O-glycosylation. Using the anti-HCRPs serum, we find secreted HCRPs in Helix nervous tissue isotonic extracts and in culture medium conditioned by Helix ganglia. In addition, we demonstrate expression of HCRPs on neuronal soma and on neurite extensions. Functionally, in Helix neurons, the antisense HCRP2 mRNA counteracts neurite elongation, and the recombinant HCRP2 protein exerts a strong positive effect on neurite growth when used as substrate. These data point to HCRPs as novel neurite growth-promoting molecules expressed in invertebrate nervous tissue.

Molluscan cells in culture: primary cell cultures and cell lines

“…Importantly, cells in culture have been validated as accurately reflecting in vivo neuronal function by cell ablation-complementation (Syed et al 1992), and by anti-sense blocking (Milanese et al 2009). In other studies, in vitro vs. in vivo cellular responses to specific chemical agents were compared (Fiumara et al 2005) and found to be similar.…”

“…The following are examples of the main types of research conducted using cultured neuronal cells. (1) identification and functional characterization of neurotrophic factors regulating neurite outgrowth and regeneration (Spence et al 1998; Goldberg 1998; Munno et al 2000; Dmetrichuk et al 2008; Milanese et al 2009; Nejatbakhsh et al 2011 and others ), (2) growth cone motility and development (Spencer et al 1998; Dmetrichuk et al 2008; Suter 2011), (3) neurite-soma and soma-soma synaptogenesis (Munno et al 2000; Hu et al 2004; Onizuka et al 2012) and (4) neuronal receptors and cell-to-cell neurotransmitter signaling (White and Laczmarek 1997; Mapara et al 2008; Giachello et al 2010; Ye et al 2010). …”

The mouse F3/contactin glycoprotein

“…In addition related molecular species have been recently demonstrated in the nervous tissue of the terrestrial snail Helix Pomatia. 83,84 Together, these data support a highly conserved role for these molecules along phylogenesis.…”