ATP + 3-O-[N-Acetyl-beta-D-galactosaminyl-(1->3)-N-acetyl-beta-D-glucosaminyl-(1->4)-alpha-D-mannosyl]-L-threonyl-[protein] <=> ADP + 3-O-[N-Acetyl-beta-D-galactosaminyl-(1->3)-N-acetyl-beta-D-glucosaminyl-(1->4)-alpha-D-(6-phospho)mannosyl]-L-threonyl-[protein]