Vitamin A is an essential nutrient necessary for numerous basic physiological functions, including reproduction and development, immune cell differentiation and communication, as well as the perception of light. To evade the dire consequences of vitamin A deficiency, vertebrates have evolved specialized metabolic pathways that enable the absorption, transport, and storage of vitamin A acquired from dietary sources as preformed retinoids or provitamin A carotenoids. This evolutionary advantage requires a complex interplay between numerous specialized retinoid-transport proteins, receptors, and enzymes. Recent advances in molecular and structural biology resulted in a rapid expansion of our understanding of these processes at the molecular level. This progress opened new avenues for the therapeutic manipulation of retinoid homeostasis. In this review, we summarize current research related to the biochemistry of carotenoid and retinoid-processing proteins with special emphasis on the structural aspects of their physiological actions. This article is part of a Special Issue entitled Carotenoids recent advances in cell and molecular biology edited by Johannes von Lintig and Loredana Quadro.

维生素 A 是许多基本生理功能所必需的必需营养素，包括生殖和发育、免疫细胞分化和通讯以及光感知。为了避免维生素 A 缺乏的可怕后果，脊椎动物进化出了专门的代谢途径，能够吸收、运输和储存从饮食来源获得的维生素 A，如预形成的类视黄醇或维生素 A 原类胡萝卜素。这种进化优势需要众多专门的类视黄醇转运蛋白、受体和酶之间复杂的相互作用。分子和结构生物学的最新进展导致我们在分子水平上对这些过程的理解迅速扩展。这一进展为类维生素A稳态的治疗操纵开辟了新途径。在这篇综述中，我们总结了当前与类胡萝卜素和类视黄醇加工蛋白的生物化学相关的研究，特别强调了它们生理作用的结构方面。本文是 Johannes von Lintig 和 Loredana Quadro 编辑的题为类胡萝卜素在细胞和分子生物学中的最新进展的特刊的一部分。