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Find a Protein by Name: Using UniProt Like a Pro

How to search UniProt for any protein, get the canonical human entry, and use the accession ID in papers and tools. Includes famous examples (insulin, p53, spike, BRCA1).

Ryan Bethencourt
April 19, 2026
8 min read

Every protein has a unique ID — here's how to find it

Scientific names for proteins can get messy. "Insulin" is actually a family — there are bovine, porcine, and human versions, and the A and B chains are separately listed. "p53" has a half-dozen aliases (TRP53 in mouse, TP53 gene in human, just "53 kDa tumor antigen" in older papers).

UniProt fixes this with one unique accession ID per protein per species. This guide walks through how to find it.

Tip
Short version: go to uniprot.org, type a name, filter to "Reviewed" + your species. The accession in the first column (like P01308) is what you want.

Step 1: Know what you're searching for

  • A common name (insulin, hemoglobin, spike protein). Easy start, but may return many hits.
  • A gene name (INS, HBB, ACE2). More precise — most genes encode one protein.
  • A UniProt ID (P01308). The most precise — one entry, one answer.
  • A sequence. For novel or unfamiliar proteins. UniProt's BLAST tool compares your sequence against the database.

Step 2: Search UniProt

Go to uniprot.org and type your query. A list comes back. Two critical filters on the left side:

  • Reviewed (Swiss-Prot) — manually curated. For well-studied proteins, always start here.
  • Organism — narrow to Homo sapiens for human, Mus musculus for mouse, etc.

What you'll typically want: "Reviewed + Homo sapiens" narrows 200 results to the one or two canonical human entries.

Step 3: Grab the accession

The accession is the column labeled "Entry" — typically starts with P, Q, O, or A. Copy it.

Famous examples:

  • P01308 — Insulin (human)
  • P69905 — Hemoglobin alpha (human)
  • P68871 — Hemoglobin beta (human)
  • P04637 — p53 tumor suppressor (human)
  • P0DTC2 — SARS-CoV-2 Spike glycoprotein
  • Q9Y261 — FOXA2 (liver transcription factor)
  • P38398 — BRCA1

Step 4: Look it up

With the accession in hand, open ProteinLab and paste it in. You get the plain-English summary: what it does, diseases it's linked to, drugs that target it, pathways it's part of, where it lives in the cell.

Bonus: finding proteins by sequence

Got an amino-acid sequence from somewhere (a paper, a sequencing result, a protein extract)? Run it through BLAST on UniProt. BLAST compares your sequence against every known protein and returns the closest matches with an E-value (statistical significance — lower is better).

Typical workflow:

  • Paste your sequence into the UniProt BLAST search.
  • Pick the top hit (usually the exact match if you have one).
  • Follow its accession into the full entry.
  • Copy that accession, plug into ProteinLab for the plain-English view.

Why bother learning this

Once you know the accession pattern, every scientific paper and biomedical news article gets more navigable. "A mutation in P04637 reduces binding to MDM2" becomes actionable — you know exactly what the paper means and where to learn more. UniProt is the scientific community's shared address book for proteins. ProteinLab is your quick-lookup tool on top of that.

Frequently Asked Questions

What's a UniProt ID?

A unique accession number like P01308 (human insulin) or P04637 (human p53). The first letter P means 'Swiss-Prot' (curated); Q and A prefixes denote 'TrEMBL' (computationally annotated but not manually curated). For human proteins you almost always want a P-accession.

What if there are multiple UniProt entries for 'insulin'?

Every species has its own entry. Human insulin is P01308, mouse insulin is P01326, bovine insulin is P01317. Same protein, different species. Be explicit about which species you want. UniProt's search filters for 'reviewed' + 'Homo sapiens' give you the human curated entry.

How do gene names relate to UniProt IDs?

Most proteins have a gene name (INS for insulin, TP53 for p53, BRCA1 for BRCA1). These come from HGNC (for humans) or MGI (for mice). UniProt links them — search for the gene name and you'll get the protein entry. Some proteins have aliases or historical names; UniProt lists all of them.

What about PDB IDs?

PDB (Protein Data Bank) identifies 3D structures, not proteins. Insulin's UniProt ID is P01308, but there are hundreds of PDB structures for insulin (1AI0, 2HIU, etc.) each representing a specific crystal or experiment. UniProt entries link to relevant PDB structures.

How do I search by function?

UniProt has 'GO term' search (Gene Ontology). Want all human proteins involved in 'DNA repair'? Search with GO:0006281. Want all kinases? Search the family keyword. Our ProteinLab is for quick individual lookups — for bulk queries, go to uniprot.org directly.

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