Integrin alpha-PS1/beta-PS is a receptor for laminin (PubMed:7972082). Integrin alpha-PS2/beta-PS is a receptor for Tig, wb and Ten-m (PubMed:7924982, PubMed:7972082, PubMed:9660786). Contributes to endodermal integrity and adhesion between the midgut epithelium and the surrounding visceral muscle (PubMed:15469969). Essential for migration of the primordial midgut cells and for maintaining, but not establishing, cell polarity in the midgut epithelium (PubMed:15469969). The two beta subunits mediate midgut migration by distinct mechanisms: beta-PS requires rhea/talin and Itgbn does not (PubMed:15469969). Required for rhea/talin correct cellular localization in the midgut (PubMed:15469969). Required for many embryonic (dorsal closure and somatic muscle attachments) and postembryonic developmental processes (attachment between cell layers of imaginal disks, organization of ommatidial arrays and flight muscle development) (PubMed:8119134, PubMed:7924982, PubMed:7972082, PubMed:10821184). Involved in the function and/or development of the olfactory system (PubMed:10821184). In the testes, essential for shv-dependent maintenance of somatic hub cells and their localization to the apical tip (PubMed:27191715). Plays a role in timely border cell migration during oogenesis (PubMed:19035354). Heterodimer of an alpha and a beta subunit. Beta-PS associates with either alpha-PS1, alpha-PS2, alpha-PS3, alpha-PS4 or alpha-PS5. In ovary, localizes to the apical, lateral and basal membranes of follicle cells through oogenesis stage 10A. Apical membrane expression peaks at oogenesis stages 9 and 10A in columnar follicle cells overlying the oocyte but decreases in the most posterior follicle cells. Thereafter, it is down-regulated. Localization to lateral and basal membranes persists during dorsal appendage morphogenesis. In ovaries, strongly expressed in follicle cells (PubMed:19035354). In oocytes, expressed in the forming dorsal appendages (at protein level) (PubMed:19035354). Expressed in the embryonic dorsal cuticle, the larval eye and the wing imaginal disk (PubMed:8119134). In testes, detected at the interface between somatic hub cells and cyst stem cells (PubMed:27191715). In zygotic mutant embryos, midgut forms primary constrictions but fails to elongate and the visceral muscle does not flatten but remains attached to the midgut epithelium. Embryos lacking maternal and zygotic mys show a delay in midgut migration. Mutant larvae present an olfactory phenotype, showing reduced response to isoamyl acetate but normal response to ethyl acetate. The absence of the beta-PS subunit results in detachment and rounding up of the muscles, thus the gene encoding beta-PS is called myospheroid. Belongs to the integrin beta chain family.