{"@type": "dcat:Dataset", "accessLevel": "public", "bureauCode": ["009:25"], "contactPoint": {"@type": "vcard:Contact", "fn": "NIH", "hasEmail": "mailto:info@nih.gov"}, "description": "Background\n          Alternative mRNA splicing of \u03b1i2, a heterotrimeric G protein \u03b1 subunit, has been shown to produce an additional protein, termed s\u03b1i2. In the s\u03b1i2 splice variant, 35 novel amino acids replace the normal C-terminal 24 amino acids of \u03b1i2. Whereas \u03b1i2 is found predominantly at cellular plasma membranes, s\u03b1i2 has been localized to intracellular Golgi membranes, and the unique 35 amino acids of s\u03b1i2 have been suggested to constitute a specific targeting signal.\n        \n        \n          Results\n          This paper proposes and examines an alternative hypothesis: disruption of the normal C-terminus of \u03b1i2 produces an unstable protein that fails to localize to plasma membranes. s\u03b1i2 is poorly expressed upon transfection of cultured cells; however, radiolabeling indicated that \u03b1i2 and s\u03b1i2 undergo myristoylation, a co-translational modification, equally well suggesting that protein stability rather than translation is affected. Indeed, pulse-chase analysis indicates that s\u03b1i2 is more rapidly degraded compared to \u03b1i2. Co-expression of \u03b2\u03b3 rescues PM localization and increases expression of s\u03b1i2. In addition, \u03b1i2A327S, a mutant previously shown to be unstable and defective in guanine-nucleotide binding, and \u03b1i2(1\u2013331), in which the C-terminal 24 amino acids of \u03b1i2 are deleted, show a similar pattern of subcellular localization as s\u03b1i2 (i.e., intracellular membranes rather than plasma membranes). Finally, s\u03b1i2 displays a propensity to localize to potential aggresome-like structures.\n        \n        \n          Conclusions\n          Thus, instead of the novel C-terminus of s\u03b1i2 functioning as a specific Golgi targeting signal, the results presented here indicate that the disruption of the normal C-terminus of \u03b1i2 causes mislocalization and rapid degradation of s\u03b1i2.", "distribution": [{"@type": "dcat:Distribution", "description": "Visit the original government dataset for complete information, documentation, and data access.", "downloadURL": "https://www.ncbi.nlm.nih.gov/pmc/articles/PMC116600/", "mediaType": "text/html", "title": "Official Government Data Source"}], "identifier": "https://healthdata.gov/api/views/t3hb-jaa8", "issued": "2025-07-14", "keyword": ["g-protein-signaling", "mrna-splicing", "nih", "protein-localization", "protein-stability"], "landingPage": "https://healthdata.gov/d/t3hb-jaa8", "modified": "2025-09-06", "programCode": ["009:033"], "publisher": {"@type": "org:Organization", "name": "National Institutes of Health"}, "theme": ["NIH"], "title": "Characterization of subcellular localization and stability of a splice variant of G alpha"}