Cdk4 Gene is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
CDK4 encodes cyclin-dependent kinase 4, a serine/threonine kinase that forms a complex with D-type cyclins (CYCLIN D1, D2, D3) to drive cell cycle progression from G1 to S phase. CDK4 is a key regulator of the cell cycle and is frequently dysregulated in cancer. In the nervous system, CDK4 plays important roles in neurogenesis, synaptic plasticity, and cell cycle control. Aberrant CDK4 activation is implicated in neuronal death in neurodegenerative diseases [1][2].
| Attribute |
Value |
| Gene Symbol |
CDK4 |
| Full Name |
Cyclin-Dependent Kinase 4 |
| Chromosomal Location |
12q14.1 |
| NCBI Gene ID |
1019 |
| Ensembl ID |
ENSG00000136492 |
| UniProt ID |
P11802 |
| Aliases |
CDK4, PSK-J3 |
CDK4 spans ~4.5 kb:
- Exons: 8 coding exons
- Transcript: ~2.2 kb mRNA
- Protein: 303 amino acids, ~34 kDa
CDK4 regulates:
- G1/S transition — Phosphorylates RB
- E2F release — Enables S-phase genes
- Cyclin D binding — Required for activity
- Thr172 phosphorylation — Activation
CDK4 in:
- Restriction point — G1 checkpoint
- DNA damage response — Can be inhibited
- Contact inhibition — Growth factor dependent
In neurons:
- Cell cycle exit — Post-mitotic neurons exit cycle
- Synaptic plasticity — Regulates synaptic proteins
- DNA repair — Cell cycle genes in repair
CDK4 in AD:
- Cell cycle re-entry — Neurons re-enter cycle inappropriately
- Tau phosphorylation — CDK4 can phosphorylate tau
- Neuronal death — Cycle activation leads to death
- Therapeutic target — CDK4 inhibitors
- Cell cycle activation — Seen in PD brains
- Dopaminergic loss — CDK4 in neuron death
- Ischemic injury — CDK4 activated after stroke
- PMID:8340146 — Discovery of CDK4
- PMID:10625657 — CDK4 structure and function
- PMID:11025718 — CDK4 in cell cycle
- PMID:21479819 — CDK4 in neurodegeneration
The study of Cdk4 Gene 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.
CDK4 is the key G1 kinase:
- G1 progression: Essential for G1/S transition
- Retinoblastoma phosphorylation: Releases E2F
- Cyclin D partnership: CDK4-cyclin D complexes
- Growth factor signaling: Links external signals to cell cycle
- Cyclin D1-3: Three cyclin D isoforms
- INK4 inhibitors: p16INK4a, p15INK4b, p18INK4c, p19INK4d
- CIP/KIP inhibitors: p21CIP1, p27KIP1
- Phosphorylation: Inhibitory (T172) and activating sites
CDK4 in the nervous system:
- Developmental expression: High in neural progenitors
- Adult brain: Low baseline, inducible
- Activity-dependent: Regulated by neuronal activity
- Glia: Present in astrocytes and microglia
CDK4 in AD:
- Neuronal cell cycle: Pathological re-entry
- Amyloid response: Aβ activates CDK4
- Tau kinase: Phosphorylates tau protein
- Synaptic plasticity: Role in memory formation
- Dopaminergic neurons: Cell cycle alterations
- α-Synuclein phosphorylation: Potential substrate
- Mitochondrial dysfunction: Links to energy metabolism
- Neuroinflammation: Cyclin D in glial activation
¶ Stroke and Brain Injury
- Ischemic stroke: CDK4 activation after injury
- Neurogenesis: Role in neural stem cells
- Reparative processes: Tissue remodeling
Cdk4 knockout mice:
- Viable: Survive to adulthood
- Growth retardation: Smaller body size
- Diabetes: β-cell proliferation defects
- Neural phenotypes: Some developmental defects
- Neuronal CDK4: Neuronal-specific expression
- p16INK4a models: Tumor suppressor studies
- AD models: APP/PS1 crossed with CDK4
| Drug |
Approval |
Primary Indication |
| Palbociclib |
FDA approved |
Breast cancer |
| Ribociclib |
FDA approved |
Breast cancer |
| Abemaciclib |
FDA approved |
Breast cancer |
- Brain cancer: Glioma therapy potential
- Neurodegeneration: Protective effects
- Challenges: Blood-brain barrier penetration
- Combination therapy: With other agents
CDK4 links growth factor signaling to cell cycle progression. In the brain, dysregulated CDK4 activity contributes to neuronal dysfunction in AD and PD. CDK4/6 inhibitors approved for cancer may have therapeutic potential in neurodegeneration.
- CDK4 in Alzheimer's disease pathogenesis (2007)
- Cell cycle kinases in neurodegeneration (2013)
- CDK4/6 inhibitors for AD therapy (2019)
- Tau phosphorylation by CDK4 (2011)