Figure 6.

Schematic of a potential reversible adhesive system in T. mediterranea. This is an oversimplified model, which might not include all involved proteins. Attachment: Tmed-ap1, Tmed-ap2 (with predicted o-glycosylation sites), and Tmed-ap3 are secreted and possibly subsequently crosslinked by Tmed-tyr1. The positively charged lysine residues of Tmed-ap3 interact with the Kringle-domain-containing microvilli-membrane-bound Tmed-krg1. Detachment: A possibly negatively charged releasing molecule is secreted from the releasing gland cell (not shown) and interferes with Tmed-ap3 binding to Tmed-krg1, additionally masking the positively charged Tmed-ap3-lysines, thus effectively supersedingTmed-krg1 from Tmed-ap3.