Chaperone Properties of Pdia3 Participate in Rapid Membrane Actions of 1α,25-Dihydroxyvitamin D3

Abstract

Protein disulfide isomerase family A, member 3 (Pdia3) mediates many of the plasma membrane (PM)-associated rapid responses to 1α,25-dihydroxyvitamin D3 (1α,25[OH]2D3). It is not well understood how Pdia3, which is an endoplasmic reticulum (ER) chaperone, functions as a PM receptor for 1α,25(OH)2D3. We mutated 3 amino acids (K214 and R282 in the calreticulin interaction site and C406 in the isomerase catalytic site), which are important for Pdia3's ER chaperone function, and examined their role in responses to 1α,25(OH)2D3. Pdia3 constructs with and without the ER retention signal KDEL were used to investigate the PM requirement for Pdia3. Finally, we determined whether palmitoylation and/or myristoylation were required for Pdia3-mediated responses to 1α,25(OH)2D3. Overexpressing the Pdia3 R282A mutant in MC3T3-E1 cells increased PM phospholipase A2-activating protein, Rous sarcoma oncogene (c-Src), and caveolin-1 but blocked increases in 1α,25(OH)2D3-stimulated protein kinase C (PKC) seen in cells overexpressing wild-type Pdia3 (Pdia3Ovr cells). Cells overexpressing Pdia3 with K214A and C406S mutations had PKC activity comparable to untreated controls, indicating that the native response to 1α,25(OH)2D3 also was blocked. Overexpressing Pdia3[-KDEL] increased PM localization and augmented baseline PKC, but the stimulatory effect of 1α,25(OH)2D3 was comparable to that seen in wild-type cultures. In contrast, 1α,25(OH)2D3 increased prostaglandin E2 in Pdia3[±KDEL] cells. Although neither palmitoylation nor myristoylation was required for PM association of Pdia3, myristoylation was needed for PKC activation. These data indicate that both the chaperone functional domains and the subcellular location of Pdia3 control rapid membrane responses to 1α,25(OH)2D3.

Signaling components of the 1α,25(OH)2D3-dependent Pdia3 receptor complex are required for Wnt5a calcium-dependent signaling

“…Previously, we reported that 1α,25(OH) 2 D 3 membrane associated receptor, Pdia3, is present in plasma membrane compartments called caveolae (52). We also showed that PLAA and CaM are present in caveolae, where their interaction with Pdia3 receptor complex is critical for transducing the 1α,25(OH) 2 D 3 signal (12,13).…”

ESWT Enhances Expression of Pdia-3 which is a Key Factor of 1α,25-Dihydroxyvitamin D3 Rapid Membrane Signaling Pathway in Treatment of Early Osteoarthritis Knee

“…Jiaxuan et al found that in Pdia-3-silenced (Sh-Pdia-3) cells, 1α,25(OH)2D3 failed to stimulate PKC and PGE2 reaction and in Pdia-3 overexpression cells (Ov-Pdia-3), the respond to 1α,25(OH)2D3 were augmented. They suggested the Pdia3 could be a determining factor correlating directly with the magnitude of the membrane response to 1α,25(OH)2D3 [32]. The principal findings of this study showed that application of ESWT induced Pdia-3 up-regulation leading to subchondral bone remolding after ACLT OA of knee in rats.…”

Identification of a novel Protein Disulfide-isomerase A3 (PDIA3) transcript variant as a potential biomarker associated with late stage prostate cancer

“…Numerous reports demonstrate that Vitamin D has an antitumor effect since it stimulates differentiation, increases apoptosis and inhibits proliferation, invasiveness and metastasis of cancer cells (13)(14)(15). Two receptors are involved in the activation of the Vitamin D signaling pathway and its mediated effects: The classic nuclear vitamin D receptor (VDR) and the protein disulfide isomerase family A, member 3 (PDIA3) receptor (16). VDR is a receptor localized in the cytosol that gets activated upon binding with vitamin D which initiates its heterodimerization with the RXR receptor.…”

“…Thus, VDR is responsible of the "genomic or long-term actions" which are the activation of gene transcription by chromatin remodeling and the regulation of vitamin D biosynthesis 4 (18). The PDIA3 receptor is a chaperone localized mainly in the endoplasmic reticulum and it is responsible for "non-genomic or rapid actions" of vitamin D in the plasma membrane (16). These actions include the regulation of intracellular, extranuclear pathways and signaling cascades, such as the activation of the protein kinase C (PKC) pathway and the calcium transport (16).…”

“…The PDIA3 receptor is a chaperone localized mainly in the endoplasmic reticulum and it is responsible for "non-genomic or rapid actions" of vitamin D in the plasma membrane (16). These actions include the regulation of intracellular, extranuclear pathways and signaling cascades, such as the activation of the protein kinase C (PKC) pathway and the calcium transport (16). The role of PDIA3 in cancer regulation remain controversial since some studies suggest that it is responsible of the activation of proapoptotic pathways (19,20) and other studies that it is associated with cancer proliferation, inhibition of the apoptosis and poor prognosis (21, 22).…”