Proteoglycan form and function: A comprehensive nomenclature of proteoglycans

Abstract

We provide a comprehensive classification of the proteoglycan gene families and respective protein cores. This updated nomenclature is based on three criteria: Cellular and subcellular location, overall gene/protein homology, and the utilization of specific protein modules within their respective protein cores. These three signatures were utilized to design four major classes of proteoglycans with distinct forms and functions: the intracellular, cell-surface, pericellular and extracellular proteoglycans. The proposed nomenclature encompasses forty-three distinct proteoglycan-encoding genes and many alternatively-spliced variants. The biological functions of these four proteoglycan families are critically assessed in development, cancer and angiogenesis, and in various acquired and genetic diseases where their expression is aberrant.

TNF-α–stimulated fibroblasts secrete lumican to promote fibrocyte differentiation

“…Lumican is a small leucine-rich proteoglycan related to fibromodulin, decorin, and biglycan (42). Lumican has a protein core of ∼40 kDa, but is usually secreted as a higher molecular weight proteoglycan, with varying amounts keratan sulfate glycosaminoglycan (43,44).…”

Endorepellin-evoked Autophagy Contributes to Angiostasis

“…Perlecan is a large modular proteoglycan that belongs to the pericellular and basement membrane class of proteoglycans (1)(2)(3). Its protein core alone is ϳ500 kDa and is comprised of five domains, with three heparan sulfate chains attached at the N terminus.…”

“…1 Both authors contributed equally to this work. 2 uble endorepellin induces autophagy in endothelial cells via the binding of its LG1/2 domains to VEGFR2 (47). This process occurs independently of the ␣2␤1 integrin and induces several autophagic markers (Beclin 1, LC3, and p62) under nutrientenriched conditions (47).…”

Proteoglycans in normal physiology and carcinogenesis

“…Степень сульфатирования молекулы ГАГ может варьировать в широких пределах (0-4 SO 4 2-групп/диса-харид) и определяет способность ГАГ/ПГ взаимодей-ствовать с широким кругом различных биологически активных лигандов (в отличие от нейтральных молекул гликопротеинов) [2].…”