Glycobiology——The “Dark Matter”of Life Sciences

Like proteins and nucleic acids, sugars and lipids are essential macromolecules that constitute biological structures and complete physiological functions. However, compared with proteins and nucleic acids, the structures of sugars and lipids are difficult to analyze and belong to the “Dark Matter” in cells. Glycobiology is recognized as a high challenge in the life science industry (Figure 1). Sugar is essential for life: Sugar molecules, represented by glucose, are one of the main sources of energy for cell metabolism. Cell walls in plants are composed of cellulose, and glycosylation is also one of the important forms of Posttranslational modifications (PTM), which can significantly expand the functional diversity of proteins. Glycosylated proteins are involved in many life processes, such as signaling, immune response and cell differentiation. However, the stereochemical complexity of glycan molecules hinders the systematic study of glycan molecules, and the lack of information on glycan structure severely limits the understanding of biomolecular group’s function.

Figure 1 

On March 28, 2024, The research group of Ning Yan/Chuangye Yan/Junmin Pan published the title "Structure-guided discovery of protein and glycan components in natural fiber villi" online in the journal Cell in native mastigonemes, the 3.0A resolution cryo-electron microscopic structure of Mastigoneme isolated from Chlamydomonas rhineae cilia was reported. The villi is a slender structure extending outward from the ciliary membrane. It was found that the main body of the villi formed a superhelical fiber structure, and each complete helix was composed of four pairs of antiparallel Mastigoneme-like protein 1 (Mst1).

In this study, the research team used the methods of biophysics, cell biology and bioinformatics to explain the molecular principle of glycan molecules participating in the construction of biomacromolecular architectures. Plants and algae are known to have a unique form of hyp-o-glycosylation, in which the glycan module consists mainly of arabinose and a small amount of galactose. This hypho-dependent form of glycosylation is the basis for the normal life activities of plants and algae.