Guanine nucleotide-binding proteins (G proteins) are involved as modulators or transducers in various transmembrane signaling systems. The G(i) proteins are involved in hormonal regulation of adenylate cyclase: they inhibit the cyclase in response to beta-adrenergic stimuli. May play a role in cell division. Regulates the cell surface density of dopamine receptors DRD2 by sequestrating them as an intracellular pool. G proteins are composed of 3 units; alpha, beta and gamma. The alpha chain contains the guanine nucleotide binding site. In this context, interacts with GNB2 (PubMed:28219978). Interacts with GPSM1 (By similarity). Interacts with RGS12 and RGS14 (By similarity). Interacts with UNC5B (PubMed:12359238). Interacts (inactive GDP-bound form) with NUCB1 (via GBA motif); the interaction leads to activation of GNAI3 (By similarity). Interacts (inactive GDP-bound form) with CCDC88C/DAPLE (via GBA motif) (PubMed:26126266). Interacts (inactive GDP-bound form) with CCDC8A/GIV (via GBA motif) (PubMed:19211784). Interacts with CXCR1 and CXCR2 (PubMed:8662698). Localizes in the centrosomes of interphase and mitotic cells. Detected at the cleavage furrow and/or the midbody. (Microbial infection) Deamidated at Gln-205 by Photorhabdus asymbiotica toxin PAU_02230, blocking GTP hydrolysis of heterotrimeric GNAQ or GNA11 and G-alphai (GNAI1, GNAI2 or GNAI3) proteins, thereby activating RhoA. Belongs to the G-alpha family. G(i/o/t/z) subfamily.