Involved in the pollen tube perception of the female signal. ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Homodimer. Interacts with MIK1, MIK2 and LURE1.2. LURE1.2 enhances the heterodimerization of MDIS1 with MIK1 or MIK2. LURE1.2 binding triggers endocytosis in the pollen tube tip. A number of isoforms are produced. According to EST sequences. Expressed in pollen tubes and seedlings. Phosphorylated by MIK1. Decreased micropylar guidance and fertilization efficiency. Belongs to the protein kinase superfamily. Ser/Thr protein kinase family.