Cell surface expression of multiple structurally and functionally distinct prostaglandin E2 (PGE2) receptors (Rs), designated the EP1, EP2, EP3, and EP4 Rs, is a principal determinant of the diverse cellular effects of PGE2. The RNK-16 line of rat large granular lymphocytes, which has served as a model for natural killer cells, coexpresses a mean of 1092 EP3 Rs and EP4 Rs per cell with a mean Kd of 2.7 nM. The presence of the EP3 and EP4 Rs and the absence of the EP1 and EP2 Rs were revealed by inhibition of [3H]PGE2 binding by the EP3/EP1R agonist sulprostone, the EP3/EP2/EP4R agonist M&B 28767, and the EP2/EP4/EP3R agonist misoprostol but not by the EP1R antagonist SC-19220 or the EP2R agonist butaprost. Functional EP4 R expression was confirmed by finding that PGE2 and misoprostol, but not butaprost or sulprostone, evoked increases in the intracellular concentration of cyclic AMP ([cAMP]) in RNK-16 cells. Matrix metalloproteinase (MMP)-1 and -3 were identified by zymography and Western blots as the principal MMPs secreted by RNK-16 cells. Secretion of both MMPs by RNK-16 cells attained a maximal level after 24 h of incubation and was enhanced significantly by 10(-9) to 10(-7) M PGE2, 10(-6) M misoprostol, and 10(-4) M dibutyryl cyclic AMP, but not by the EP3R agonist sulprostone. Thus, the effect of PGE2 on RNK-16 cell MMP secretion is mediated by an EP4 R-dependent mechanism involving increases in [cAMP]i. The migration of RNK-16 cells across micropore filters, without or with a layer of Matrigel, was stimulated chemokinetically by PGE2 and misoprostol. PGE2-elicited chemokinesis of RNK-16 cells across a Matrigel model basement membrane, but not across a microfilter alone, was suppressed by the GM 6001 inhibitor of MMP activities. Stimulation of MMP activities in RNK-16 cells by the EP4R thus facilitates migration of the NK cells across vascular basement membranes.