Cloning and characterization of a phospholipase C-beta isoform from the sea urchin Lytechinus pictus.

Calcium is a ubiquitous intracellular signaling molecule controlling a wide array of cellular processes including fertilization and egg activation. The mechanism for triggering intracellular Ca(2+) release in sea urchin eggs during fertilization is the generation of inositol-1,4,5-trisphosphate by phospholipase C (PLC) hydrolysis of phosphatidylinositol-4,5-bisphosphate. Of the five PLC isoforms identified in mammals (beta, gamma, delta, epsilon and zeta), only PLCgamma and PLCdelta have been detected in echinoderms.

The mechanisms of cell membrane resealing in rabbit corneal epithelial cells.

Purpose: To examine membrane repair mechanisms in rabbit corneal epithelial (RCE) cells.

Methods: Microneedle puncture and fluorescent dye loss were used to wound membranes and assay resealing, respectively. Different repair mechanisms were detected pharmacologically and with antisense oligonucleotides.

Molecular regulation of membrane resealing in 3T3 fibroblasts.

Membrane resealing in mammalian cells after injury depends on Ca(2+)-dependent fusion of intracellular vesicles with the plasma membrane. When cells are wounded twice, the subsequent resealing is generally faster. Physiological and biochemical studies have shown the initiation of two different repair signaling pathways, which are termed facilitated and potentiated responses.

Molecular Cloning and Characterization of Protein Kinase C from the Sea Urchin Lytechinus pictus: (protein kinase C/cDNA cloning/polyclonal antibodies/developmental expression).

Protein kinase C (PKC) has been shown to play a role in events involved in fertilization such as activation of the Na /H antiporter and an NADPH dependent oxidase. In addition, it is involved in cell fate programming later in development of the sea urchin embryo. In order to further address the role of PKC in sea urchin development, we have screened a Lytechinus pictus ovary tissue cDNA library and identified one clone for sea urchin protein kinase C (suPKC1).