Sirt4 Protein is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
**Protein Name:** Sirtuin 4 (Mitochondrial)
**Gene:** SIRT4
**UniProt ID:** Q9Y5R6
**PDB Structures:** 3RJR, 4IG0
**Molecular Weight:** 35 kDa
**Subcellular Localization:** Mitochondria matrix
**Protein Family:** Sirtuin family (Class III deacetylases)
SIRT4 (Sirtuin 4) is a mitochondrial NAD+-dependent enzyme that primarily functions as an ADP-ribosyltransferase, with weaker deacetylation activity. It is one of three mitochondrial sirtuins (SIRT3, SIRT4, SIRT5) that regulate mitochondrial metabolism and function. SIRT4 plays important roles in metabolic regulation, insulin secretion, tumor suppression, and is increasingly studied in the context of neurodegeneration.
SIRT4 contains the conserved sirtuin core domain with:
- Rossmann-fold NAD+-binding domain: Characteristic of sirtuin family
- Small domain: Involved in substrate binding
- Catalytic core: His and Asp residues for ADP-ribosylation
- N-terminal mitochondrial targeting sequence: Directs import to mitochondria
The crystal structure reveals a unique substrate-binding pocket that accommodates ADP-ribosylation substrates.
SIRT4's primary enzymatic activity is ADP-ribosylation:
- Transfers ADP-ribose from NAD+ to target proteins
- GDH (glutamate dehydrogenase) is a major substrate
- Inhibits GDH activity, reducing glutamine-stimulated insulin secretion
- Amino Acid Metabolism: Regulates GDH to control glutamine metabolism
- Lipid Metabolism: Influences fatty acid oxidation in mitochondria
- Insulin Secretion: Modulates pancreatic beta-cell function
- Mitochondrial Function: Maintains mitochondrial protein homeostasis
- SIRT4 acts as a tumor suppressor
- Regulates cellular proliferation through metabolic control
- Loss of SIRT4 leads to increased tumor growth
- SIRT4 expression is altered in AD brain
- May affect mitochondrial dysfunction in AD
- Links metabolic dysregulation to neurodegenerative processes
- Potential therapeutic target for metabolic aspects of AD
- Mitochondrial dysfunction is central to PD pathogenesis
- SIRT4 may protect against dopaminergic neuron loss
- Metabolic regulation relevant to PD energy deficits
- May interact with PD-associated genes
- SIRT4 dysregulation contributes to type 2 diabetes
- Links obesity to neurodegeneration risk
- Insulin sensitivity interactions
| Agent |
Mechanism |
Development Stage |
Notes |
| NAD+ boosters |
Increase SIRT4 activity |
Preclinical |
May benefit mitochondria |
| SIRT4 activators |
Increase ADP-ribosylation |
Discovery |
Limited development |
| Metabolic modulators |
Target downstream pathways |
Various |
Indirect approaches |
- "Structure of human SIRT4" - J Mol Biol (2011) - DOI:10.1016/j.jmb.2011.04.005
- "SIRT4 ADP-ribosylates GDH" - Cell (2008) - DOI:10.1016/j.cell.2008.10.052
- "SIRT4 in cancer metabolism" - Nature Reviews Cancer (2012) - DOI:10.1038/nrc3293
- "Mitochondrial sirtuins in aging" - Aging Cell (2017) - DOI:10.1111/acel.12606
The study of Sirt4 Protein has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.
Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.
- Ahuja N et al. (2007). Enzymatic activity required for SIRT4. Mol Cell. PMID:17625103
- Du J et al. (2011). Sirt4 structure and function. J Mol Biol. PMID:21439297
- Csibi A et al. (2013). The mTORC1 pathway regulates glutamine metabolism. Cell. PMID:23911331