# The Transporter Classification Database (TCDB)

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA, SAN DIEGO · 2020 · $315,000

## Abstract

ABSTRACT
 Transporters catalyze entry and exit of molecules into and out of cells and organelles. They
achieve cellular homeostasis, are responsible for multidrug resistance in pathogens and tumors, and,
when defective, cause dozens of important human genetic diseases. Our laboratory maintains, updates
and improves the Transporter Classification Database, TCDB, which houses the Transporter
Classification (TC) system, adopted officially by the International Union of Biochemistry and Molecular
Biology (IUBMB). TCDB is the internationally acclaimed, carefully annotated, universal standard for
classifying and providing information about transporters and transport-related proteins in all major
domains of life. It presents sequence, biochemical, physiological, pathological, structural and
evolutionary data about these proteins and the transport systems they comprise. It uses a successful
system of classification based on transporter class, subclass, family, subfamily, individual transport
system and constituent proteins. It also includes a superfamily hyperlink.
 In this competitive renewal of GM0077402, we propose to continue to expand, update, and
semi-automate TCDB. Our specific aims are to (1) upgrade TCDB by characterizing and categorizing
protein domains and their topologies, motifs, repeat units, functional interactions, alternative splicing
and post-translational modifications, (2) expand TCDB by implementing novel pipelines for data entry
that will increase the coverage of transport diversity in TCDB while describing more effectively the
complexity of multicomponent transport systems, (3) enter into TCDB transporter modulators such as
activators, inhibitors, drugs and xenobiotics as well as internal and external conditions that influence
transporter activities, while generating an ontology to describe the effects of chemical modulators that
will complement our substrate ontology, (4) incorporate into TCDB synthetic pores/channels (TC
subclass 1.D), and carriers (TC subclass 2.B), (5) introduce into TCDB connections between transport
and metabolism and (6) expand our plans for long-term TCDB sustainability.

## Key facts

- **NIH application ID:** 9895808
- **Project number:** 5R01GM077402-14
- **Recipient organization:** UNIVERSITY OF CALIFORNIA, SAN DIEGO
- **Principal Investigator:** MILTON H. SAIER
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $315,000
- **Award type:** 5
- **Project period:** 2006-04-01 → 2022-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9895808

## Citation

> US National Institutes of Health, RePORTER application 9895808, The Transporter Classification Database (TCDB) (5R01GM077402-14). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9895808. Licensed CC0.

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