Function, structure, and regulation of Iron Regulated Transporter 1

Iron (Fe) is an essential mineral for the growth and development of plants, as it serves as a vital co-factor for a multitude of enzymes that participate in a variety of physiological processes. Plants obtain Fe from the soil through their Fe uptake systems. Non-graminaceous plants utilize a reduction-based system for Fe uptake, which involves the conversion of Fe(III) to Fe(II) and subsequent absorption of Fe(II). Iron-Regulated Transporter 1 (IRT1), a predominant transporter of Fe(II), is a central element of the Fe uptake mechanism in plants. In Arabidopsis thaliana, IRT1 exhibits a broad-spectrum of substrate specificity and functions as a transceptor, capable of sensing the levels of its non-Fe metal substrates. Over the past two decades, significant advancements have been achieved in understanding the functions and regulatory mechanisms of IRT1 and its orthologs across various plant species. This review provides a systematic overview of the functional attributes of IRT1, with a particular focus on the intricate regulatory mechanisms at the transcriptional, post-transcriptional, and post-translational levels that are pivotal in modulating the expression and activity of IRT1. Moreover, we offer insights and directions for future research on this important transporter.