RESUMO
The active form of vitamin D, 1,25-dihydroxyvitamin D3, is known to act via VDR (vitamin D receptor), affecting several physiological processes. In addition, PDIA3 (protein disulphide-isomerase A3) has been associated with some of the functions of 1,25-dihydroxyvitamin D3. In the present study we used siRNA-mediated silencing of PDIA3 in osteosarcoma and prostate carcinoma cell lines to examine the role(s) of PDIA3 for 1,25-dihydroxyvitamin D3-dependent responses. PDIA3 silencing affected VDR target genes and significantly altered the 1,25-dihydroxyvitamin D3-dependent induction of CYP24A1, essential for elimination of excess 1,25-dihydroxyvitamin D3. Also, PDIA3 silencing significantly altered migration and proliferation in prostate PC3 cells, independently of 1,25-dihydroxyvitamin D3. 1,25-Dihydroxyvitamin D3 increased thermostability of PDIA3 in cellular thermal shift assay, supporting functional interaction between PDIA3 and 1,25-dihydroxyvitamin D3-dependent pathways. In summary, our data link PDIA3 to 1,25-dihydroxyvitamin D3-mediated signalling, underline and extend its role in proliferation and reveal a novel function in maintenance of 1,25-dihydroxyvitamin D3 levels.
Assuntos
Movimento Celular , Proliferação de Células , Isomerases de Dissulfetos de Proteínas , Receptores de Calcitriol , Vitamina D3 24-Hidroxilase , Isomerases de Dissulfetos de Proteínas/metabolismo , Isomerases de Dissulfetos de Proteínas/genética , Humanos , Receptores de Calcitriol/metabolismo , Receptores de Calcitriol/genética , Linhagem Celular Tumoral , Vitamina D3 24-Hidroxilase/genética , Vitamina D3 24-Hidroxilase/metabolismo , Calcitriol/farmacologia , Calcitriol/metabolismo , Inativação Gênica , RNA Interferente Pequeno/metabolismo , RNA Interferente Pequeno/genética , Vitamina D/metabolismo , Vitamina D/farmacologia , Vitamina D/análogos & derivados , Masculino , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologiaRESUMO
Determining the levels of protein-protein interactions is essential for the analysis of signaling within the cell, characterization of mutation effects, protein function and activation in health and disease, among others. Herein, we describe MolBoolean - a method to detect interactions between endogenous proteins in various subcellular compartments, utilizing antibody-DNA conjugates for identification and signal amplification. In contrast to proximity ligation assays, MolBoolean simultaneously indicates the relative abundances of protein A and B not interacting with each other, as well as the pool of A and B proteins that are proximal enough to be considered an AB complex. MolBoolean is applicable both in fixed cells and tissue sections. The specific and quantifiable data that the method generates provide opportunities for both diagnostic use and medical research.
