Chondroitin sulfate proteoglycan 4 regulates zebrafish body axis organization via Wnt/planar cell polarity pathway.

Yen-Hua Lee,I-Hsuan Liu,Wei-Chun Huangfu,Koichi Kawakami,Michael Klymkowsky

doi:10.1371/journal.pone.0230943

Abstract

Pericellular and extracellular proteoglycans play an important role in modulating morphogen gradients and signal transductions. Chondroitin sulfate proteoglycan 4 (Cspg4) is a membrane spanning proteoglycan expressed in immature progenitor cells and cancer cells. Cspg4 participates in cellular events such as proliferation, migration and signal transduction, and these events are generally important for embryo development. In this study, we characterized Cspg4 for its roles in zebrafish embryonic development. Our results demonstrated that cspg4 was maternally expressed from 0 to 3 hours post fertilization (hpf) and expressed in the anterior and posterior embryo end after 9 hpf. Knocking-down cspg4 resulted in a shorter anterior-posterior axis than control embryo, which could be rescued by co-injecting wnt11 mRNA suggesting that Cspg4 regulates body axis organization through modulating the Wnt/planar cell polarity signaling pathway. In addition, overexpressing cspg4 caused cyclopia. The Cspg4 transmembrane domain mutant embryo phenocopied the global over-expression of cspg4 mRNA and led to cyclopia with a very low penetrance. Our results demonstrated that the quantitatively and spatially accurate distribution of Cspg4 is critical for body axis and midline development during gastrulation.

Highlights

Chondroitin sulfate proteoglycan 4 (Cspg4), known as neuron glial antigen 2 (NG2), high molecular weight melanoma-associated antigen (HMW-MAA), or melanoma chondroitin sulfate proteoglycan (MCSP), is a membrane-spanning glycoprotein with a large extracellular domain that can link glycosaminoglycan (GAG) chains [1]
Cspg4 has been reported to play a part in regulating cell motility by its chondroitin sulfate GAGs (CS-GAGs) chains, extracellular domain or cytoplasmic domain of core protein; for example, the PDZ domain and PKCα phosphorylation site [42,43,44,45]
It is possible that zebrafish Cspg4 regulates cell motility during gastrulation by these functional domains

Summary

Introduction

Chondroitin sulfate proteoglycan 4 (Cspg4), known as neuron glial antigen 2 (NG2), high molecular weight melanoma-associated antigen (HMW-MAA), or melanoma chondroitin sulfate proteoglycan (MCSP), is a membrane-spanning glycoprotein with a large extracellular domain that can link glycosaminoglycan (GAG) chains [1]. The extracellular domain includes three sub-domains: the N-terminal laminin G-type domain, the central domain containing multiple chondroitin sulfate acceptor sites and collagen V and VI binding sites and the juxtamembrane domain with at least two proteolytic sites [2]. Cspg regulates zebrafish early development in study design, data collection and analysis, decision to publish, or preparation of the manuscript

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Conclusion