| Source | Publication date | URL / DOI | Model / organism | Main finding relevant to function / localization / pathway | Quantitative / statistical data reported |
|---|---|---|---|---|---|
| Aizawa 2013 | Jan 2013 | https://doi.org/10.1371/journal.pone.0053706 ; DOI: 10.1371/journal.pone.0053706 | Mouse and human SMP30/GNL structural/biochemical study; directly relevant to rat ortholog Q03336 because regucalcin/SMP30 identity and family/function are conserved | Confirms regucalcin = SMP30 = gluconolactonase (EC 3.1.1.17); enzyme catalyzes formation of L-gulono-γ-lactone in the ascorbate pathway; adopts a six-bladed β-propeller fold with a divalent-metal active site; substrate-binding cavity and lid loop support folded L-gulonate binding; active-site residues include Glu18, Asn154, Asp204, with Asn103 important for catalysis; broad in vitro activity toward multiple aldonolactones; original SMP30 purification/history linked to rat liver (pqac-00000000, pqac-00000003, pqac-00000004, pqac-00000006, pqac-00000022, pqac-00000024, pqac-00000028) | Reported GNL activity at 25°C: mouse SMP30/GNL (1.30 ± 0.03) × 10^3 mmol·min^-1·mg^-1; human SMP30/GNL 799 ± 60 mmol·min^-1·mg^-1. ICP-MS detected Zn2+, Mn2+, Mg2+, and Ca2+; ~half of purified protein contained Ca2+ before dialysis; mouse and human proteins are 89% identical (pqac-00000002, pqac-00000022, pqac-00000027) |
| Inoue 2023 | Oct 2023 | https://doi.org/10.3177/jnsv.69.388 ; DOI: 10.3177/jnsv.69.388 | FAO rat liver cells | In rat hepatocyte-derived cells, resveratrol upregulates SMP30/regucalcin through AMPK/Sirt1-Foxo1 signaling; SMP30 is framed as a liver-enriched, age-declining gluconolactonase linked to antioxidant protection and hepatic ascorbate biology; supports a pathway role in oxidative-stress resistance rather than only a passive senescence marker (pqac-00000008, pqac-00000010) | Resveratrol treatment for 24 h increased SMP30 expression; resveratrol was noncytotoxic up to 50 mM, with 30 mM used as the maximum tested concentration. AMPK inhibitor Compound C, Sirt1 inhibitor EX-527, and Foxo1 inhibitor AS1842527 abolished/decreased the SMP30 induction. The excerpt reports qualitative reduction in H2O2-induced LDH release but no fold-change values for SMP30 are given in the retrieved text (pqac-00000008, pqac-00000010) |
| Arakawa 2023 | Dec 2023 | https://doi.org/10.3177/jnsv.69.420 ; DOI: 10.3177/jnsv.69.420 | ODS rat (male, 4 weeks old) | In vitamin C-defective ODS rats, ascorbate deficiency decreases hepatic SMP30 protein without changing hepatic/renal SMP30 mRNA, while SMP30 increases in serum extracellular vesicles (EVs); this links SMP30/regucalcin to liver injury signaling, EV release, and STAT3-associated acute-phase responses under ascorbate deficiency (pqac-00000013, pqac-00000014, pqac-00000015, pqac-00000016) | Design: n=5/group; pair-fed for 14 d; AsA-sufficient rats received 0.1% ascorbic acid in drinking water. Liver AsA: 0.836 ± 0.041 vs 0.086 ± 0.004 mmol/g; serum AsA: 25.10 ± 1.395 vs 1.62 ± 0.059 mM (sufficient vs deficient). AST: 94.06 ± 6.675 vs 119.56 ± 0.750 IU/L; ALT: 26.26 ± 1.968 vs 23.86 ± 0.702 IU/L; AST/ALT ratio: 3.63 ± 0.248 vs 4.79 ± 0.261. Serum CINC-1: 89.36 ± 4.487 vs 110.26 ± 4.293 pg/mL. Final body weight: ~142.0 vs 140.3 g; water consumption 16.47 ± 0.523 vs 18.61 ± 0.980 g/d (pqac-00000013, pqac-00000016) |
| Schreurs 2023 | Oct 2023 | https://doi.org/10.1038/s41598-023-43567-z ; DOI: 10.1038/s41598-023-43567-z | Male Wistar rats, kidney cortex proteomics | In rat kidney cortex, Rgn/regucalcin is downregulated in cyclosporine-treated animals relative to dehydrated rats; authors interpret Rgn as a renal calcium-regulatory, anti-apoptotic factor, and its downregulation as part of a toxin-associated proximal tubular injury/senescence signature rather than simple dehydration injury (pqac-00000017, pqac-00000018) | Design: control n=6; dehydration n=8; cyclosporine n=8. Dehydration: water deprivation 10 h/24 h, 5 d/week for 4 weeks with heat exposure during deprivation. Cyclosporine: oral gavage 40 mg/kg for 4 weeks. No numeric fold-change or p-value for Rgn was given in the retrieved excerpt; result is directional from iTRAQ-based cortical proteomics and pathway analysis (pqac-00000017, pqac-00000018) |
| Yamaguchi 2023 (review) | Nov 2023 | https://doi.org/10.3390/cancers15225489 ; DOI: 10.3390/cancers15225489 | Review emphasizing human cancer, but synthesizes extensive rat cell and rat in vivo data | Positions regucalcin as a multifunctional suppressor that localizes in cytoplasm and nucleus; maintains intracellular Ca2+ homeostasis by activating Ca2+ pumps in plasma membrane, mitochondria, and ER; inhibits kinases, phosphatases, nitric oxide synthase, cysteinyl protease, aminoacyl-tRNA synthetase, DNA/RNA synthesis, and cell-cycle progression; summarizes rat liver, kidney, prostate, and hepatoma studies showing anti-proliferative and homeostatic roles (pqac-00000009, pqac-00000012) | Quantitative values are sparse in the retrieved review excerpts; most findings are qualitative. The review notes rat liver regucalcin induction after partial hepatectomy and changes in Ca2+-ATPase activities, but no fold-changes are provided in the retrieved text (pqac-00000009, pqac-00000012) |
| Hicks 2011 | Nov 2011 | https://doi.org/10.1002/prot.23135 ; DOI: 10.1002/prot.23135 | Comparative protein superfamily / computational-mechanistic context | Places SMP30/regucalcin in the strictosidine synthase-like / SGL subgroup of six-bladed β-propeller enzymes with conserved metal-binding ligands; supports identity of SMP30 with regucalcin and interprets it as a metal-dependent lactonase involved in L-ascorbic acid biosynthesis in non-primate mammals, while also noting catalytic promiscuity (e.g., organophosphate hydrolysis) (pqac-00000005) | No rat-specific quantitative expression values in the retrieved excerpt; mechanistic context is qualitative, emphasizing conserved active-site metal ligands and family-level functional inference rather than kinetics (pqac-00000005) |


*Table: This table compiles the most relevant structural, mechanistic, and recent rat-focused evidence for Rgn/regucalcin/SMP30 (UniProt Q03336). It highlights how the literature supports its identity as a metal-dependent gluconolactonase and a broader regulator of calcium homeostasis, oxidative stress, and injury responses.*