# IsoProDB: an integrated map of human protein isoforms for accelerated research

**Authors:** Sreelakshmi Pathappillil Soman, Samseera Ummar, Muktar Ahmed, Prathik Basthikoppa Shivamurthy, Sourav Sreelan, Poornima Ramesh, Mahammad Nisar, Yashwanth Subbannayya, Rajesh Raju

PMC · DOI: 10.1093/database/baag015 · 2026-03-26

## TL;DR

IsoProDB is a comprehensive database mapping human protein isoforms to help researchers study their roles in health and disease.

## Contribution

IsoProDB integrates and aligns protein isoforms from multiple sources with detailed functional and structural annotations.

## Key findings

- IsoProDB includes 110,149 human protein isoforms from 20,536 genes with features like PTMs and domain architecture.
- The database supports comparative analysis of isoforms to identify conserved and nonconserved functional elements.
- It links isoforms to disease relevance and provides visual tools for multiomics exploration.

## Abstract

Emerging studies highlight the importance of protein isoforms, which often exhibit distinct functional roles and contribute to physiological diversity, disease mechanisms, and phenotypic variation, despite originating from the same gene. However, comprehensive isoform-level resources that characterize protein isoforms remain limited. IsoProDB is an integrative and unified one-stop database that aligns protein isoforms from RefSeq and UniProtKB, enabling cross-sequence visualization for protein isoform analysis in humans. It integrates features such as domain architecture, intrinsically disordered regions, sequence variants, transmembrane topology, and 52 distinct post-translational modifications (PTMs) mapped to protein isoforms from multiple resources. Currently, IsoProDB enables users to perform gene wise comparative analyses across 110 149 protein isoforms derived from 20 536 protein-coding genes for all integrated features, supported by effective visualizations. This provides insights into conserved and nonconserved PTM sites, domains, isoform-specific membrane localization, the impact of variants on protein function, and disease relevance across protein isoforms. With specific isoforms emerging as markers and theragnostic targets for various disorders, IsoProDB is integrated with multiple global resources for easy navigation and exploration of multiomics information on isoforms.

## Linked entities

- **Species:** Homo sapiens (taxon 9606)

## Full-text entities

- **Genes:** CHEK1 (checkpoint kinase 1) [NCBI Gene 1111] {aka CHK1, OZEMA21}, SYK (spleen associated tyrosine kinase) [NCBI Gene 6850] {aka IMD82, p72-Syk}, ABCC4 (ATP binding cassette subfamily C member 4 (PEL blood group)) [NCBI Gene 10257] {aka MOAT-B, MOATB, MRP4}, STAT3 (signal transducer and activator of transcription 3) [NCBI Gene 6774] {aka ADMIO, ADMIO1, APRF, HIES}, BRCA1 (BRCA1 DNA repair associated) [NCBI Gene 672] {aka BRCAI, BRCC1, BROVCA1, FANCS, IRIS, PNCA4}, PGF (placental growth factor) [NCBI Gene 5228] {aka D12S1900, PGFL, PIGF, PLGF, PlGF-2, SHGC-10760}, ERBB2 (erb-b2 receptor tyrosine kinase 2) [NCBI Gene 2064] {aka CD340, HER-2, HER-2/neu, HER2, MLN 19, MLN-19}, FLT1 (fms related receptor tyrosine kinase 1) [NCBI Gene 2321] {aka FLT, FLT-1, VEGFR-1, VEGFR1}
- **Diseases:** lung and colorectal cancers (MESH:D015179), cardiovascular, renal, neurological, and metabolic disorders (MESH:D024821), HCC (MESH:D006528), breast cancer (MESH:D001943), leukemia (MESH:D007938), HCC tumour (MESH:D009369), metastasis (MESH:D009362), pre-eclampsia (MESH:D011225)
- **Chemicals:** trastuzumab (MESH:D000068878)
- **Species:** Homo sapiens (human, species) [taxon 9606]
- **Mutations:** start/stop

## Figures

3 figures with captions in the complete paper: https://tomesphere.com/paper/PMC13019292/full.md

---
Source: https://tomesphere.com/paper/PMC13019292