Ultrastructural Localization of Spicule Matrix Proteins in Normal and Metalloproteinase Inhibitor-Treated Sea Urchin Primary Mesenchyme Cells

Eric P. Ingersoll, Kent L. Mcdonald, Fred H. Wilt

Research output: Contribution to journalArticle

20 Scopus citations

Abstract

Studies of the sea urchin larval skeleton have contributed greatly to our understanding of the process of biomineralization. In this study we have undertaken an investigation of the morphology of skeleton formation and the localization of proteins involved in the process of spicule formation at the electron microscope level. Sea urchin primary mesenchyme cells undergo a number of morphological changes as they synthesize the larval skeleton. They form a large spicule compartment that surrounds the growing spicule and, as spicule formation comes to an end, the density of the cytoplasm decreases. Inhibition of spicule formation by specific matrix metalloproteinase inhibitors or serum deprivation has some subtle effects on the morphology of cells and causes the accumulation of specific classes of vesicles. We have localized proteins of the organic matrix of the spicule and found that one protein, SM30, is localized to the Golgi apparatus and transport vesicles in the cytoplasm as well as throughout the occluded protein matrix of the spicule itself. This localization suggests that SM30 is an important structural protein in the spicule. Another spicule matrix protein, SM50, has a similar cytoplasmic localization, but in the spicule much of it is localized at the periphery of the spicule compartment, and consequently it may play a role in the assembly of new material onto the growing spicule or in the maintenance of the integrity of the matrix surrounding the spicule.

Original languageEnglish (US)
Pages (from-to)101-112
Number of pages12
JournalJournal of Experimental Zoology Part A: Comparative Experimental Biology
Volume300
Issue number2
DOIs
StatePublished - Dec 1 2003

All Science Journal Classification (ASJC) codes

  • Animal Science and Zoology

Fingerprint Dive into the research topics of 'Ultrastructural Localization of Spicule Matrix Proteins in Normal and Metalloproteinase Inhibitor-Treated Sea Urchin Primary Mesenchyme Cells'. Together they form a unique fingerprint.

Cite this