Protein / target
Myeloid cell surface antigen CD33
Protein at a glance
Biological role
Protein tyrosine phosphatase activator
Strongest disease association
Alzheimer's Disease
Therapeutic position
Established drug target
Research activity
Emerging research
Derived from structured UniProt, Open Targets and literature data on this page.
Protein profile
Canonical identity and biological annotation from UniProt.
Function overview
Sialic-acid-binding immunoglobulin-like lectin (Siglec) that plays a role in mediating cell-cell interactions and in maintaining immune cells in a resting state.
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Sialic-acid-binding immunoglobulin-like lectin (Siglec) that plays a role in mediating cell-cell interactions and in maintaining immune cells in a resting state (PubMed:10611343, PubMed:11320212, PubMed:15597323). Preferentially recognizes and binds alpha-2,3- and more avidly alpha-2,6-linked sialic acid-bearing glycans (PubMed:7718872). Upon engagement of ligands such as C1q or syalylated glycoproteins, two immunoreceptor tyrosine-based inhibitory motifs (ITIMs) located in CD33 cytoplasmic tail are phosphorylated by Src-like kinases such as LCK (PubMed:10887109, PubMed:28325905). These phosphorylations provide docking sites for the recruitment and activation of protein-tyrosine phosphatases PTPN6/SHP-1 and PTPN11/SHP-2 (PubMed:10206955, PubMed:10556798, PubMed:10887109). In turn, these phosphatases regulate downstream pathways through dephosphorylation of signaling molecules (PubMed:10206955, PubMed:10887109). One of the repressive effect of CD33 on monocyte activation requires phosphoinositide 3-kinase/PI3K (PubMed:15597323)
Subcellular location
Domains and Gene Ontology detail (26)Hide
Domains & features
Gene Ontology
- Ccell surface
- Cexternal side of plasma membrane
- CGolgi apparatus
- Cperoxisome
- Cplasma membrane
- Cspecific granule membrane
- Ctertiary granule membrane
- Fcarbohydrate binding
- Fprotein phosphatase binding
- Fprotein tyrosine phosphatase activator activity
- Fsialic acid binding
- Fsignaling receptor activity
Biological roles
What this protein does, drawn together from its UniProt function, Gene Ontology terms and Reactome pathways.
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Cell proliferation & survival
- ·negative regulation of cell population proliferation
Immune signalling
- ·immune response-inhibiting signal transduction
- ·negative regulation of interleukin-1 beta production
- ·negative regulation of interleukin-8 production
Cell adhesion
- ·cell adhesion
- ·cell-cell adhesion
Concepts derived from UniProt GO Reactome — each badge above shows which sources supported that role.
Approved medicines with mapped indications
Approved therapies targeting this protein, grouped by what they are approved to treat — the disease-first view of the medicines below. Relationships come from the canonical approved-indication graph (ChEMBL phase-4), the same source as the drug cards.
Broader indication categories (1)Hide
Broad umbrella indications (e.g. “Neoplasms”). Shown here because every medicine also appears under a more specific disease above — kept for completeness, de-emphasised for clarity.
Approved indications from ChEMBL (phase-4), via the canonical drug→disease graph.
Drugs targeting this protein
How approved and investigational drugs engage this protein — mechanism and action type, direct vs complex targeting, and how broadly each acts across other targets. A drug-first view (the section above groups the approved ones disease-first); direct binders with few recorded targets are listed first.
Myeloid cell surface antigen CD33 binding agent
Indicated for Leukemia, Myeloid, Leukemia, Myeloid, Acute, Neoplasms
ChEMBL mechanism, action type, target identity and approved indications. Open Targets clinical status.
Translational evidence
Why this target matters therapeutically, strongest evidence first. Disease associations are gene-level (via the gene that encodes this protein) and open into the full confidence synthesis; the development universe, tractability and safety annotations are target-level, from Open Targets.
Strongest disease associations · via encoding gene CD33
Gene-level evidence surfaced through the gene CD33that encodes this protein — not a direct protein–disease relationship. Ranked by Forefront's causal-directness weighting, so genetically- and clinically-evidenced diseases lead over ones that merely share the literature.
View evidence synthesis (5)Hide
This ranking differs from Open Targets' own: re-weighting moves genetically-evidenced diseases above more heavily co-mentioned ones. The evidence agreement range shows how closely the independent evidence families agree — it is not a statistical confidence interval, and nothing here is fitted to outcome data. Derived from Open Targets evidence types under Forefront weighting; the per-type scores above show the calculation.
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Drug development
5 compounds recorded · 1 approved · 4 in clinical development
View all recorded compounds (5)Hide
Open Targets known-drugs universe. Drug name and highest clinical stage only — the disease relationship is NOT read from this slice (it carries trial-context noise); approved indications come from the canonical graph above.
Tractability
Small molecules — Emerging
Antibodies — Strong
Protein degraders — Emerging
Other modalities — Strong
View underlying tractability evidence (9)Hide
Raw Open Targets tractability assessment buckets, by modality.
Clinical trials
Trials of drugs that target this protein — reached indirectly through those drugs, so a trial listed here studies the drug, not the protein. Ranked by active status, then clinical phase and recency, and spread across the targeting drugs.
View all trials (26)Hide
ClinicalTrials.gov via the drug-target graph.
What's happening now
Recent therapeutic activity around this target — regulatory actions, clinical trials and safety signals for a drug that targets this protein, plus publications where such a drug is a genuine subject. Every item is reached indirectly through the drug, not the protein itself; incidental mentions (a paper that merely measures a drug) and press items are excluded.
- Trial status changed
A Pilot Study of Liposomal Cytarabine and Daunorubicin (CPX-351) in Combination With Gemtuzumab Ozogamicin (GO) in Relapsed Refractory Patients With Acute Myeloid Leukemia (AML) and Post-Hypomethylating Agent (Post-HMA) Failure High-Risk Myelodysplastic Syndrome (HR-MDS)
- Trial results posted
Fractionated Gemtuzumab Ozogamicin Followed by Non-engraftment Donor Leukocyte Infusions for Relapsed/Refractory Acute Myeloid Leukemia
- Trial status changed
Fractionated Gemtuzumab Ozogamicin Followed by Non-engraftment Donor Leukocyte Infusions for Relapsed/Refractory Acute Myeloid Leukemia
- Regulatory approval
Approval: Mylotarg (EMA)
Objective event titles are shown unmodified; the event kind and significance line are derived from structured fields. Forefront AttentionEvent stream aggregating Europe PMC Regulatory filings ClinicalTrials.gov.
Research activity
Papers linked directly to this protein. This is the protein's own literature — descriptor-derived papers are kept separate below.
Most cited
Recent
Europe PMC papers linked directly to this protein.