Possible role in cell adhesion. Minor involvement in the establishment of the oocyte anterior-posterior length. Heterodimer of an alpha and a beta subunit. Alpha-PS4 associates with beta-PS (By similarity). Expressed in lamellocytes (at protein level). At the anterior end of the oocyte, expressed in the follicle cells that will form the operculum and the micropyle. Weakly expressed during late-oogenesis. Belongs to the integrin alpha chain family. Intron retention. Intron retention.