1.A.130.1.1
Nortia (Nta), the Ca²⁺ channel protein of 895 aas and ~ 10 TMSs in a 1 + 1 + 2 + 6 [2 + 2 + 2) TMS arrangement (O22752); Feronia (Fer) a receptor-like kinase and constituent of a transmembrane calmodulin-gated calcium (Ca²⁺) channel protein complexof 542 aas, an MLO-like protein, and Lorleei (Lre, glycosyl PI anchor protein of 165 aas with 2 TMSs, one N-terminal and one C-terminal (B3GS44) (Gao et al. 2022). The channel protein (Nortia) functions in conjunction with these two other proteins, Feronia (Fer), a receptor-like protein kinase, and Lorelei (Lre), a GPI-anchored protein.  See the family description, paragraph 1 and Gao et al. 2022 for more details. Two pollen-tube-derived small peptides that belong to the rapid alkalinzation factor (RALF) family seem to be ligands for the FER-LRE co-receptor, which in turn recruits NTA to the plasm membrane.  NTA initiates Ca²⁺ spiking in the synergid cells, for pollen tube reception.  Thus, the FER-LRE-NTA complex forms a receptor-channel complex in the female cell to recognize male signals and trigger tertilization.