The Evolution and Structure/Function of bHLH-PAS Transcription Factor Family

Authors

Hailey E Edwards
Daniel A Gorelick

Publication Date

6-30-2022

Journal

Biochemical Society Transactions

DOI

10.1042/BST20211225

PMID

35695677

PMCID

PMC10584024

PubMedCentral® Posted Date

10-18-2023

PubMedCentral® Full Text Version

Author MSS

Published Open-Access

yes

Keywords

Animals, Aryl Hydrocarbon Receptor Nuclear Translocator, Basic Helix-Loop-Helix Transcription Factors, Dimerization, Mammals, Receptors, Aryl Hydrocarbon

Abstract

Proteins that contain basic helix-loop-helix (bHLH) and Per-Arnt-Sim motifs (PAS) function as transcription factors. bHLH-PAS proteins exhibit essential and diverse functions throughout the body, from cell specification and differentiation in embryonic development to the proper function of organs like the brain and liver in adulthood. bHLH-PAS proteins are divided into two classes, which form heterodimers to regulate transcription. Class I bHLH-PAS proteins are typically activated in response to specific stimuli, while class II proteins are expressed more ubiquitously. Here, we discuss the general structure and functions of bHLH-PAS proteins throughout the animal kingdom, including family members that do not fit neatly into the class I-class II organization. We review heterodimerization between class I and class II bHLH-PAS proteins, binding partner selectivity and functional redundancy. Finally, we discuss the evolution of bHLH-PAS proteins, and why a class I protein essential for cardiovascular development in vertebrates like chicken and fish is absent from mammals.