Functional differences between yeast and human TFIID are localized to the highly conserved region

Area of Science:

• Molecular Biology
• Genetics
• Biochemistry

Background:

• Transcription Factor II D (TFIID) is a highly conserved general transcription factor essential for eukaryotic gene expression.
• TFIID's core domains across eukaryotes share high sequence identity (>80%) and similar biochemical properties.

Purpose of the Study:

• To investigate the functional differences between yeast and human TFIID despite their conserved core domains.
• To identify the specific regions within TFIID responsible for species-specific functional incompatibilities in yeast.

Main Methods:

• Functional analysis of yeast cells expressing human TFIID and yeast-human hybrid TFIID constructs.
• Assessing cell growth as a measure of TFIID functionality in vivo.
• Comparative analysis of core domain regions to pinpoint functional determinants.

Main Results:

• Yeast cells expressing human TFIID exhibit severely impaired growth compared to those with endogenous yeast TFIID.
• The N-terminal region of TFIID is not essential for yeast cell viability, as the core domain alone supports growth.
• Specific regions within the conserved core domain of TFIID are responsible for the observed species-specific functional differences.

Conclusions:

• Functional incompatibility between yeast and human TFIID arises from variations within their conserved core domains.
• These species-specific differences in TFIID may stem from altered DNA-binding affinities or distinct interactions with transcription machinery components.
• Understanding these variations provides insights into the evolution and regulation of fundamental transcription processes.