Involved in pollen tube guidance into micropyle. Participates in perception of the ovule-secreted peptide signal LURE1. Interacts with PRK6. Expressed in mature pollen and in germinating pollen tubes. Palmitoylated. No visible phenotype. Lip1 and lip2 double mutants have a reduced male transmission. Belongs to the protein kinase superfamily. Ser/Thr protein kinase family.