← BioTransfer smORF Atlas · healthy-tissue companion to Riboseq ATLAS
Ribosome Profiling · Healthy Human Tissues

smORF Atlas

A free, searchable atlas of 7,767 small ORFs (smORFs) and microproteins actively translated across healthy human tissues and cell types, mapped by ribosome profiling. Companion to the cancer-focused Riboseq ATLAS — use both to ask whether a cancer nuORF is also expressed in normal tissue.

What is the smORF Atlas? What can I find here? ▼

The core idea: Healthy human cells don't just make the ~20,000 textbook proteins — they also translate thousands of tiny proteins (microproteins) from small ORFs (smORFs) hidden in regions usually called "non-coding": upstream of genes (uORFs), inside long non-coding RNAs, and in alternative frames. This atlas maps which of them are switched on in normal tissue.

How were they found? Ribosome profiling (Ribo-seq) freezes ribosomes mid-translation and sequences the mRNA they are reading — direct proof a stretch of RNA is being turned into protein. Chothani et al. applied it across 11 healthy human tissues and primary cell types and called 7,767 translated smORFs.

Why does it matter? This is the healthy baseline. A novel ORF found in cancer is only a safe immunotherapy target if it is absent from normal tissue. Pairing this atlas with the cancer-focused Riboseq ATLAS lets you check exactly that — smORFs flagged ATLAS are translated in both healthy and cancer cells.

What you can do here
Search by gene or peptide

Find smORFs by host gene (e.g. ANXA11), smORF ID, or amino-acid sequence

Filter by evidence

MS-validated (protein detected), secreted (signal peptide), or also-in-cancer-ATLAS

Check conservation

Amino-acid conservation in mouse & rat — a clue to functional microproteins

Inspect structure

Exon layout, start codon, peptide & nucleotide sequence, Ensembl / GeneCards links

Database

smORF Atlas — 7,767 smORFs

614 MS-validated at protein level

46 secreted (signal peptide)

96 also in cancer Riboseq ATLAS

smORF Types

5′ uORF (upstream)

ncRNA-embedded

Out-of-frame / alternative

Near-cognate starts (CTG, GTG, TTG…)

Healthy Tissues & Cell Types (11)

Brain · Heart · Kidney · Fat

Embryonic stem cells (ES)

Fibroblasts · Hepatocytes

HUVEC · HCAEC (endothelial)

SM · VSMC (smooth muscle)

What Ribo-seq measures

Active translation (ribosomes on mRNA) — proof the smORF makes protein in healthy cells.

Evidence Badges
MS peptide detected by mass spectrometry
SEC predicted secreted (signal peptide)
ATLAS also translated in cancer (shared stop codon with Riboseq ATLAS)
Citation

Chothani et al., A high-resolution map of human RNA translation, Mol Cell 2022.
GEO: GSE182377 · hg38 · free, no login.

Search — gene, smORF ID, or peptide
Start codon
Strand
Evidence
Chromosome
Min aa length
Max aa length
smORF IDGeneLocusaaStart PeptideMSCons (mm/rn)Evidence
Search to browse smORFs, or just hit Search to list all.
Reading the columns
AA — micropeptide length in amino acids (residues). e.g. 4 = a 4-residue microprotein.
Peptide — amino-acid sequence; a trailing _ marks the stop codon (e.g. MTHL_ = Met-Thr-His-Leu·stop).
Start — initiation codon. Many smORFs use near-cognate starts (CTG, GTG, TTG…) not just ATG.
MS — number of mass-spec peptide hits (>0 = protein product directly detected).
Cons (mm/rn) — % amino-acid conservation in mouse / rat (higher = more likely functional).
Evidence — MS validated · SEC secreted · ATLAS also translated in cancer.

Data: Chothani et al., A high-resolution map of human RNA translation, Molecular Cell 2022 · GEO GSE182377 · hg38. Conservation = % amino-acid identity in mouse (mm10) / rat (rn6). "Also in cancer ATLAS" = high-confidence shared stop-codon match to the Riboseq ATLAS (Ouspenskaia 2022). Built by Bharat Prajapati · free, no login.