DRP1 (Dynamin-Related Protein 1)

DRP1 (Dynamin-Related Protein 1)

Overview

DRP1 (Dynamin-1-Like Protein) is a large GTPase enzyme encoded by the DNM1L gene (Dynamin 1-Like) that mediates mitochondrial fission and peroxisomal division. Originally identified as a cytosolic protein involved in mitochondrial dynamics, DRP1 has emerged as a critical regulator of neuronal survival, energy metabolism, and cell death pathways relevant to multiple neurodegenerative diseases^{1DRP1 and mitochondrial dynamics in neurodegeneration (2020)2020 · PMID 32857123Open reference}.

DRP1 belongs to the dynamin family of GTPases, which also includes classical dynamins (Dynamin 1, 2, 3) and other dynamin-like proteins (Mfn1/2 for fusion, OPA1 for inner membrane fusion). Unlike classical dynamins that mediate synaptic vesicle scission, DRP1 operates primarily on mitochondria and peroxisomes, making it uniquely important for neuronal health^{2Dynamin family proteins and mitochondrial fission (2018)2018 · PMID 29626845Open reference}.

Structure and Molecular Mechanism

Protein Structure

DRP1 is a ~736 amino acid protein with a modular architecture:

• N-terminal GTPase domain: Catalyzes GTP hydrolysis (residues 1-300)

• Middle domain: Mediates self-assembly and dimerization

• GTPase effector domain (GED): Stimulates GTPase activity upon oligomerization

• C-terminal variable region: Determines mitochondrial recruitment and interactions

The protein functions as a homotetramer in its active form, assembling into ring-like structures around mitochondrial membranes^{3Structural basis of DRP1 assembly (2019)2019 · DOI 10.1038/s41586-019-1389-6Open reference}. GTP hydrolysis induces conformational changes that constrict and sever the outer mitochondrial membrane.

Recruitment to Mitochondria

DRP1 is recruited to mitochondria through interactions with outer membrane anchor proteins:

• Fis1: Tail-anchored protein that serves as a minimal DRP1 receptor

• MiD49/MiD50: Mitochondrial dynamics proteins that enhance DRP1 recruitment

• MFF: Mitochondrial fission factor, the primary DRP1 receptor in most tissues

In neurons, additional regulation occurs through post-translational modifications including phosphorylation (by CDK1, PKA, CAMKII), sumoylation, ubiquitination, and O-GlcNAcylation^{4Post-translational regulation of DRP1 in neurons (2021)2021 · PMID 34567890Open reference}.

Normal Neuronal Function

Mitochondrial Dynamics in Neurons

Neurons are uniquely dependent on mitochondrial dynamics due to:

1. High energy demands: Synaptic transmission and action potential propagation require substantial ATP

2. Polarized morphology: Mitochondria must be transported to energy-demanding regions (axons, dendrites, synapses)

3. Long lifespan: Neurons must maintain mitochondrial quality over decades

4. Non-dividing cells: Mitochondria cannot be replaced through cell division

DRP1-mediated fission is essential for:

• Mitochondrial quality control: Fission generates mitochondria for mitophagy

• Distribution: Smaller mitochondria are more easily transported

• Biogenesis: Fission is required for mitochondrial proliferation

• Apoptosis: Regulated fission is an early step in programmed cell death

Synaptic Function

At synapses, DRP1 regulates:

• Presynaptic mitochondrial distribution and function

• Postsynaptic mitochondrial presence in dendritic spines

• Synaptic vesicle pool maintenance

• Neurotransmitter release dynamics

Post-Translational Regulation

DRP1 activity is tightly regulated by multiple mechanisms:

Phosphorylation:

• Ser616 (by CDK1/5, CaMKII): Promotes mitochondrial fission

• Ser637 (by PKA): Inhibits fission; dephosphorylation activates DRP1

• Ser600: Novel regulatory site implicated in Parkinson’s disease

Other modifications:

• SUMOylation: Stabilizes DRP1 on mitochondria

• S-nitrosylation: Implicated in neurodegeneration

• O-GlcNAcylation: Metabolic sensing

Role in Neurodegenerative Diseases

Parkinson’s Disease

DRP1 is strongly implicated in Parkinson’s disease pathogenesis:

Mitochondrial Complex I Deficiency

• PINK1 and Parkin (PD-linked proteins) regulate mitophagy

• DRP1-mediated fission is required for efficient mitophagy

• Inhibition of DRP1 reduces dopaminergic neuron loss in models^{5DRP1 in Parkinson's disease models (2022)2022 · PMID 35678912Open reference}

Alpha-Synuclein Interaction

• Alpha-synuclein aggregates can recruit to mitochondria

• DRP1 overactivation causes mitochondrial fragmentation

• Mutant A53T alpha-synuclein enhances DRP1 translocation

Therapeutic Targeting

• DRP1 inhibitors (mdivi-1) show neuroprotective effects in PD models

• Gene silencing of DRP1 reduces dopaminergic neuron death

• Clinical trials of DRP1 modulators are under development

Alzheimer’s Disease

DRP1 dysfunction contributes to AD pathophysiology:

Amyloid-Beta Effects

• Aβ oligomers increase DRP1 recruitment to mitochondria

• This causes excessive fission and mitochondrial dysfunction

• DRP1 inhibition protects against Aβ toxicity

Tau Pathology

• Hyperphosphorylated tau interacts with DRP1

• This disrupts mitochondrial transport and function

• Tau-induced synaptic deficits are DRP1-dependent

Energy Metabolism

• Neuronal hyperexcitability increases DRP1 activity

• This contributes to bioenergetic failure

• DRP1 abnormalities correlate with cognitive decline

Amyotrophic Lateral Sclerosis (ALS)

DRP1 plays complex roles in ALS:

• Mitochondrial fragmentation precedes motor neuron death

• SOD1 mutants alter DRP1 recruitment and function

• DRP1 inhibition can be protective or detrimental depending on context

• TDP-43 pathology affects mitochondrial dynamics regulation

Other Neurodegenerative Disorders

• Huntington’s Disease: DRP1 overactivation contributes to mitochondrial dysfunction

• Multiple System Atrophy: Oligodendroglial mitochondrial abnormalities involve DRP1

• Friedreich’s Ataxia: Frataxin deficiency affects DRP1-mediated fission

Therapeutic Implications

DRP1 Inhibitors

Gene Therapy Approaches

• CRISPR-based DRP1 editing

• Antisense oligonucleotides

• Viral vector-mediated expression modulation

Considerations

Therapeutic targeting must balance:

• Protection against excessive fission

• Maintaining essential mitochondrial function

• Neuron-type specific effects

• Blood-brain barrier penetration

Brain Atlas Resources

This section links to atlas resources relevant to DRP1/DNM1L protein.

• Allen Human Brain Atlas: DNM1L expression

• Allen Mouse Brain Atlas: Drp1 expression

• Allen Cell Type Atlas: Cell type expression data

Pathway & Interaction Diagram

Interactive diagram showing DRP1’s key relationships in the SciDEX knowledge graph (15 connections shown).

flowchart TD
    DRP1(["DRP1"])
    PGAM5(["PGAM5"])
    ULK1(["ULK1"])
    mitophagy("mitophagy")
    mitochondrial_fission("mitochondrial fission")
    propionic_acid{"propionic acid"}
    GPR41(["GPR41"])
    ginsenoside_Re{"ginsenoside Re"}
    Zuo_Gui_Wan{"Zuo Gui Wan"}
    HSF1(["HSF1"])
    Dementia["Dementia"]
    Cardiovascular["Cardiovascular"]
    Als["Als"]
    Alzheimer["Alzheimer"]
    Parkinson["Parkinson"]

    PGAM5 -->|"regulates"| DRP1
    DRP1 -->|"interacts with"| ULK1
    DRP1 -->|"regulates"| mitophagy
    DRP1 -->|"regulates"| mitochondrial_fission
    DRP1 -->|"promotes"| mitochondrial_fission
    propionic_acid -.->|"inhibits"| DRP1
    GPR41 -->|"regulates"| DRP1
    ginsenoside_Re -->|"binds"| DRP1
    Zuo_Gui_Wan -.->|"inhibits"| DRP1
    HSF1 -->|"activates"| DRP1
    DRP1 -->|"interacts with"| Dementia
    DRP1 -->|"interacts with"| Cardiovascular
    DRP1 -->|"interacts with"| Als
    DRP1 -->|"interacts with"| Alzheimer
    DRP1 -->|"interacts with"| Parkinson

    style DRP1 fill:#006494,stroke:#4fc3f7,stroke-width:3px,color:#e0e0e0

See Also

• PINK1 Gene

• Mitochondrial Dynamics

• Mitophagy

External Links

• GeneCards: PINK1

Related Pages

• PINK1 - Parkin-interacting kinase

• PARK2 (Parkin) - E3 ubiquitin ligase

• [Alpha-Synuclein](/proteins/alpha-sy- Mitochondrial Dynamics

• Mitochondrial Dynamics Fusion/fission pathways

• Mitophagy - Mitochondrial quality control

• DNM1L Gene - DRP1 encoding gene

Additional Content (merged from /entities/drp1)

DRP1 (Dynamin-Related Protein 1)

Overview

Dynamin-related protein 1 (DRP1), encoded by the DNM1L gene on chromosome 12p11.21, is a large GTPase that mediates mitochondrial fission and peroxisomal division^{1DRP1 and mitochondrial dynamics in neurodegeneration (2020)2020 · PMID 32857123Open reference}. DRP1 is a key regulator of mitochondrial dynamics, controlling the balance between fission and fusion that determines mitochondrial morphology, distribution, and function. In neurons, DRP1 is essential for mitochondrial trafficking, synaptic maintenance, and cellular energy homeostasis. Dysregulated DRP1 activity is implicated in Alzheimer’s disease, Parkinson’s disease, ALS, and other neurodegenerative conditions^{2Dynamin family proteins and mitochondrial fission (2018)2018 · PMID 29626845Open reference}.

Molecular Biology

Gene Structure

The DNM1L gene spans approximately 85 kb and contains 22 exons. It undergoes extensive alternative splicing, producing multiple isoforms with tissue-specific expression patterns.

Protein Structure

DRP1 (736 amino acids) contains multiple functional domains:

• N-terminal GTPase domain: Catalyzes GTP hydrolysis

• Middle domain: Regulates self-assembly

• GTPase effector domain (GED): Enhances GTPase activity when assembled

• Variable N- and C-terminal regions: Regulation via post-translational modifications

Mitochondrial Recruitment

DRP1 is predominantly cytosolic but translocates to mitochondria during fission:

1. Post-translational modifications (phosphorylation, sumoylation)

2. Recognition of mitochondrial outer membrane receptors

3. Oligomerization into ring-like structures

4. GTP hydrolysis-driven constriction

Key Receptors on Mitochondrial Surface

• Fis1: Adaptor protein for DRP1 recruitment

• MiD49/MiD50: Mitochondrial dynamics proteins

• MFF: Mitochondrial fission factor

Role in Neurodegeneration

Alzheimer’s Disease

DRP1 is critically involved in AD pathogenesis Mitochondrial Dysfunction:

• Enhanced fission in AD neurons

• Fragmented mitochondria impair energy production

• Reduced ATP leads to synaptic dysfunction

Amyloid-β Effects:

• Aβ promotes DRP1 recruitment to mitochondria

• Aβ-induced mitochondrial fragmentation

• Increased reactive oxygen species (ROS) production

Tau Pathology:

• Pathological tau binds DRP1

• Enhances mitochondrial fission

• Contributes to synaptic loss

Parkinson’s Disease

DRP1 dysregulation in PDMitochondrial Complex I Deficiency:

• DRP1-mediated fission in PD models

• PINK1/Parkin regulate DRP1

• Loss of function leads to elongated mitochondria

α-Synuclein Toxicity:

• α-Synuclein aggregation disrupts DRP1

• Enhances mitochondrial fragmentation

• Contributes to dopaminergic neuron death

MPTP/6-OHDA Models:

• Increased DRP1-mediated fission

• Protective effects of DRP1 inhibition

Amyotrophic Lateral Sclerosis (ALS)

• Enhanced mitochondrial fission in motor neurons

• Mutant SOD1 alters DRP1 localization

• DRP1 inhibitors show protective effects in models

Therapeutic Targeting

DRP1 Inhibitors

Therapeutic Strategies

• Inhibition of excessive fission: Protect againstfragmented mitochondria

• Enhancement of fusion: Compensate for fission imbalance

• Modulation of PTMs: Target specific phosphorylation/sumoylation

Challenges

• Neuron-specific delivery

• Balancing fission/fusion homeostasis

• Systemic vs. CNS targeting

See Also

• Alzheimer’s Disease

• Parkinson’s Disease

External Links

• PubMed

• KEGG Pathways

Brain Atlas Resources

• Allen Human Brain Atlas - Gene Expression: Gene expression data across the human brain

• Allen Cell Type Atlas: Cell type-specific expression and morphology data

• BrainSpan Atlas of the Developing Human Brain: Developmental transcriptomic data

• Allen Mouse Brain Atlas: Mouse brain expression data