KAT6A (Lysine Acetyltransferase 6A), also known as MOZ (Monocytic Leukemia Zinc Finger Protein) or MYST3, is a histone acetyltransferase that plays crucial roles in gene transcription regulation, chromatin remodeling, and normal hematopoiesis. KAT6A is frequently involved in chromosomal rearrangements in leukemia and has emerging connections to neurodegenerative disease mechanisms through epigenetic regulation of stress response and cellular senescence pathways. [@koch2011][@sheikh2015]
KAT6A belongs to the MYST family of histone acetyltransferases, which are characterized by their conserved MYST domain comprising an acetyl-CoA binding site and a zinc finger domain. This family includes KAT5, KAT6B, KAT7, and KAT8, all of which participate in chromatin regulation and have been implicated in various diseases including cancer and neurodegeneration. [@perez2013][@shen2024]
| Property |
Value |
| Gene Symbol |
KAT6A |
| Gene Name |
Lysine Acetyltransferase 6A |
| Aliases |
MOZ, MYST3, ZNF220, KIAA1704 |
| Chromosomal Location |
8p11.21 |
| NCBI Gene ID |
9869 |
| OMIM |
603408 |
| UniProt |
Q9Y5V0 |
| Ensembl |
ENSG00000108924 |
| RefSeq |
NM_006766 |
| Protein Length |
2007 amino acids |
¶ Protein Structure and Domains
KAT6A is a large nuclear protein with multiple functional domains that enable its role in chromatin regulation and transcriptional control.
¶ Catalytic MYST Domain
The MYST domain (approximately 370 amino acids) serves as the core acetyltransferase domain. This domain:
- Binds acetyl-CoA as the cofactor for histone acetylation
- Contains a C2HC-type zinc finger that contacts DNA
- Catalyzes the transfer of acetyl groups to lysine residues on histone tails
- Shows substrate specificity for histones H3 and H4, particularly H3K9, H3K14, and H4K5/H4K8
¶ PHD Zinc Finger Domains
KAT6A contains two PHD (Plant Homeodomain) zinc finger domains:
- PHD1: Located near the N-terminus, involved in chromatin reader function
- PHD2: Positioned to recognize specific histone modifications
These PHD domains function as chromatin reader modules that recognize specific histone marks, enabling KAT6A to be targeted to genomic regions with particular epigenetic states. This targeting is essential for the precise regulation of gene expression programs.
¶ HMG Domain
The HMG (High Mobility Group) domain provides DNA-bending capability, facilitating:
- Chromatin remodeling through nucleosome displacement
- Enhancement of transcriptional activation
- Recruitment of additional transcriptional coactivators
¶ Transcriptional Activation Domains
KAT6A contains multiple transcriptional activation domains:
- N-terminal acidic activation domain
- Central proline-rich regions
- C-terminal domains mediating protein-protein interactions
These domains recruit components of the transcription machinery, including CREBBP and EP300, which are themselves major histone acetyltransferases with critical roles in neurodegeneration. [@sun2017]
KAT6A acetylates multiple histone targets with distinct biological consequences:
| Histone Site |
Biological Effect |
| H3K9 |
Transcriptional activation, euchromatin maintenance |
| H3K14 |
Chromatin opening, factor recruitment |
| H3K23 |
Long-range chromatin interactions |
| H3K27 |
Alternative activation pathway |
| H4K5 |
DNA damage response facilitation |
| H4K8 |
Replication stress response |
| H4K12 |
Cell cycle progression |
The acetylation activity of KAT6A contributes to gene regulation through several interconnected mechanisms:
-
Chromatin Compaction Relief: Histone acetylation neutralizes the positive charge on lysine residues, reducing histone-DNA interactions and promoting an open chromatin configuration accessible to transcription factors.
-
Transcription Factor Recruitment: Acetylated histone tails serve as docking sites for bromodomain-containing proteins that further promote transcription.
-
Histone Mark Crosstalk: KAT6A-mediated acetylation can prime histones for subsequent modifications, including phosphorylation and methylation.
-
Histone Variant Incorporation: KAT6A shows preference for acetylation of nucleosomes containing histone variants like H3.3, which are incorporated during transcriptionally active gene regulation.
KAT6A is essential for normal blood cell development and function: [@perez2013][@holmlund2009]
- Maintains hematopoietic stem cell (HSC) self-renewal capacity
- Regulates HSC quiescence and proliferation balance
- Essential for long-term HSC maintenance
- Critical for monocytic differentiation
- Regulates expression of myeloid lineage genes
- Controls granulocyte and macrophage development
- Involved in B and T cell development
- Regulates immunoglobulin gene recombination
- Controls T cell receptor diversity
KAT6A regulates gene expression programs through histone acetylation: [@brown2014][@yang2009]
- Acetylates promoter and enhancer regions
- Recruits RNA polymerase II cofactors
- Coordinates with pioneer transcription factors
- Maintains open chromatin states
- Facilitates enhancer-promoter interactions
- Regulates nucleosome positioning
¶ Development and Differentiation
- Essential for embryonic development
- Regulates tissue-specific gene programs
- Controls cell fate decisions
Recent research has revealed that KAT6A plays a critical role in cellular senescence: [@sheikh2015]
- KAT6A directly represses the CDKN2A locus (encoding p16INK4A and ARF)
- Loss of KAT6A leads to increased p16INK4A expression
- This regulates the transition from cellular senescence to aging
- Cellular senescence is a key contributor to age-related tissue dysfunction
- Senescent cells accumulate in aging brains
- KAT6A dysfunction may contribute to age-related neurodegeneration
KAT6A is a well-characterized oncogene in hematological cancers: [@zhou2020][@su2021]
- Chromosomal translocations create fusion oncoproteins
- Common translocation t(8;16)(p11;p13) creates KAT6A-CREBBP fusion
- KAT6A-MLL fusion proteins cause aggressive AML
- Translocations found in ~1-2% of AML cases
- KAT6A mutations associated with MDS progression
- Altered acetylation patterns in MDS bone marrow
- Poor prognosis in KAT6A-altered cases
- HDAC inhibitors show activity in KAT6A-driven leukemia
- Small molecule KAT6A inhibitors in development (e.g., WM-1119)
- Synthetic lethality approaches under investigation
KAT6A mutations cause syndromic neurodevelopmental disorders:
- Intellectual disability
- Developmental delay
- Speech and language deficits
- Craniofacial abnormalities
- Microcephaly
- Cardiac malformations
Emerging evidence links KAT6A to neurodegenerative disease mechanisms: [@tian2023][@roh2020]
- Epigenetic regulation of microglial activation genes
- Potential role in neuroinflammation modulation
- HDAC inhibitors modulate cytokine production
¶ Cognitive Decline and Aging
The relationship between KAT6A and histone deacetylases offers therapeutic opportunities: [@graff2012][@uno2020]
- Valproic acid (HDAC1/2 inhibitor) tested in AD and PD
- Vorinostat (SAHA) in clinical trials for CNS disorders
- Show neuroprotective effects in cellular and animal models
- Target HDAC4, HDAC5, HDAC6, HDAC9
- Tubastatin A (HDAC6) shows promise in PD models
- Regulates autophagy and lysosomal function
- Combined HDAC and KAT modulation approaches
- BET inhibitors as complementary strategy
- Focus on restoring transcriptional homeostasis
- WM-1119: Specific KAT6A inhibitor showing efficacy in AML
- A-485 (CREBBP/KAT6A dual inhibitor)
- Potential for neurodegenerative disease application
- HDAC inhibitors increase global histone acetylation
- Compensation for reduced KAT6A activity
- Combination approaches with CREBBP/EP300 activators
Existing HDAC inhibitors being investigated for neurodegeneration:
| Drug |
Target |
Clinical Stage |
Disease Focus |
| Valproic Acid |
HDAC1/2, 3 |
Phase 2-3 |
AD, PD |
| Vorinostat |
Class I/II HDAC |
Phase 1 |
ALS |
| Romidepsin |
HDAC1/2 |
Preclinical |
PD |
| Entinostat |
HDAC1/3 |
Phase 1 |
Brain tumors |
KAT6A interacts with multiple proteins and complexes central to transcription regulation and disease:
- CREBBP (CBP) - major transcriptional coactivator
- EP300 (p300) - related acetyltransferase
- NCOA1 - nuclear receptor coactivator 1
- NCOA2 - nuclear receptor coactivator 2
- SWI/SNF complex components
- NuRD complex members
- HDAC proteins
- RUNX1 - critical for hematopoiesis
- PU.1 (SPI1) - myeloid differentiation
- GATA family - blood cell development
- HOX genes - developmental patterning
- MLL (KMT2A) - fusion partners in leukemia
- TIF2 (NCOA2) - coactivator in tumor progression
- p53 (TP53) - tumor suppression links
KAT6A (MOZ/MYST3) is a histone acetyltransferase essential for transcriptional regulation, hematopoiesis, and cellular senescence control. While classically studied in leukemia due to its frequent involvement in chromosomal translocations, emerging research reveals connections to neurodegenerative disease through epigenetic dysregulation. The enzyme's role in maintaining chromatin openness, regulating stress response genes, and controlling cellular senescence makes it a potential therapeutic target for age-related neurological disorders. HDAC inhibitors, which oppose KAT6A function, show promise in preclinical models of Alzheimer's and Parkinson's diseases, highlighting the importance of histone acetylation balance in neuronal health and disease.
- Yang, Current Opinion in Genetics & Development (2009)
- Holmlund et al., Blood (2009)
- Merson et al., Nature Genetics (2006)
- Koch et al., Molecular Cell (2011)
- Arrowsmith et al., Nature Reviews Drug Discovery (2012)
- Kennedy et al., Proceedings of the National Academy of Sciences (2016)
- Brown et al., Genes & Development (2014)
- Sun et al., Leukemia (2017)
- Zhou et al., MOZ/KAT6A: a promising target for acute myeloid leukemia therapy, American Journal of Cancer Research (2020)
- Su et al., The role of MOZ/KAT6A in hematological malignancies, Journal of Hematology & Oncology (2021)
- Sheikh et al., MOZ inhibits senescence via the INK4A-ARF pathway, Oncogene (2015)
- Perez-Campo et al., The MYSTerious MOZ, a histone acetyltransferase, Biochemistry (2013)
- Shen et al., Histone acetyltransferase KAT6A and its role in human diseases, Frontiers in Cell and Developmental Biology (2024)
- Dang et al., Epigenetic regulation of healthspan and longevity, Current Opinion in Genetics & Development (2020)
- Uno et al., HDAC6 regulates cellular senescence, Aging Cell (2020)
- Graff et al., The potential role of HDAC inhibitors in neurodegeneration, Expert Opinion on Therapeutic Targets (2012)
- Roh et al., Epigenetic modifiers in neurodegenerative diseases, Molecules (2020)
- Tian et al., Targeting histone acetylation for neurodegenerative diseases, Frontiers in Aging Neuroscience (2023)