Tamar Gilboa - Academia.edu (original) (raw)

Papers by Tamar Gilboa

Research paper thumbnail of Endothelin-converting Enzyme-1, Abundance of Isoforms a-d and Identification of a Novel Alternatively Spliced Variant Lacking a Transmembrane Domain

Journal of Biological Chemistry, Dec 1, 2005

Endothelin-converting enzyme-1 (ECE-1) cleaves big endothelins, as well as bradykinin and ␤-amylo... more Endothelin-converting enzyme-1 (ECE-1) cleaves big endothelins, as well as bradykinin and ␤-amyloid peptide. Several isoforms of ECE-1 (a-d) have been identified to date; they differ only in their NH 2 terminus but share the catalytic domain located in the COOHterminal end. Using quantitative PCR, we found ECE-1d to be the most abundant type in several endothelial cells (EC) types. In addition to full-length ECE-1 forms we have identified novel, alternatively spliced mRNAs of ECE-1 b-d. These splice variants (SVs) lack exon 3, which codes for the transmembrane region and is present in full-length forms. SVs mRNA were highly expressed in EC derived from macro and microvascular beds but much less so in other, nonendothelial cells expressing ECE-1, which suggests that the splicing mechanism is cell-specific. Analyses of ECE-1d and its SV form in stably transfected HEK-293 cells revealed that both proteins were recognized by anti COOH-terminal ECE-1 antibodies, but anti NH 2-terminal antibodies only bound ECE-1d. The novel protein, designated ECE-1 sv, has an apparent molecular mass of 75 kDa; by using site-directed mutagenesis its start site was identified in a region common to all ECE-1 forms suggesting that ECE-1 b-d SV mRNAs are translated into the same protein. In agreement with the findings demonstrating common COOH terminus for ECE-1sv and ECE-1d, both exhibited a similar catalytic activity. However, immunofluorescence staining and differential centrifugation revealed a distinct intracellular localization for these two proteins. The presence of ECE-1sv in different cellular compartments than full-length forms of the enzyme may suggest a distinct physiological role for these proteins.

Research paper thumbnail of Characterization of endothelin-1 and nitric oxide generating systems in corpus luteum-derived endothelial cells

Reproduction, 2004

Endothelium-derived endothelin-1 (ET-1) and nitric oxide (NO) are pivotal regulators of corpus lu... more Endothelium-derived endothelin-1 (ET-1) and nitric oxide (NO) are pivotal regulators of corpus luteum (CL) function. To have a better insight into their synthesis and action, members of the ET system (ET-1, ET converting enzyme (ECE-1) isoforms a–d, ETAand ETBreceptors) along with NO synthase (NOS) isoforms – endothelial (e)NOS and inducible (i)NOS – were quantified in CL-derived endothelial cells (CLEC). The expression of these genes in microvascular CLEC, obtained by lectin-coated magnetic beads, was compared with cells removed from the luteal microenvironment and maintained in culture for different durations, and with endothelial cells (EC) derived from a large blood vessel (i.e. bovine aortic endothelial cells, BAEC). The profile of gene expression in the different EC types was determined by quantitative real-time PCR. Freshly isolated EC from mid-cycle CL exhibited high ET-1 receptor expression (both ETAand ETB), low ET-1 synthesizing ability (both prepro (pp) ET-1 and ECE-1), ...

Research paper thumbnail of Endothelin-converting Enzyme-1, Abundance of Isoforms a-d and Identification of a Novel Alternatively Spliced Variant Lacking a Transmembrane Domain

Journal of Biological Chemistry, 2005

Endothelin-converting enzyme-1 (ECE-1) cleaves big endothelins, as well as bradykinin and ␤-amylo... more Endothelin-converting enzyme-1 (ECE-1) cleaves big endothelins, as well as bradykinin and ␤-amyloid peptide. Several isoforms of ECE-1 (a-d) have been identified to date; they differ only in their NH 2 terminus but share the catalytic domain located in the COOHterminal end. Using quantitative PCR, we found ECE-1d to be the most abundant type in several endothelial cells (EC) types. In addition to full-length ECE-1 forms we have identified novel, alternatively spliced mRNAs of ECE-1 b-d. These splice variants (SVs) lack exon 3, which codes for the transmembrane region and is present in full-length forms. SVs mRNA were highly expressed in EC derived from macro and microvascular beds but much less so in other, nonendothelial cells expressing ECE-1, which suggests that the splicing mechanism is cell-specific. Analyses of ECE-1d and its SV form in stably transfected HEK-293 cells revealed that both proteins were recognized by anti COOH-terminal ECE-1 antibodies, but anti NH 2-terminal antibodies only bound ECE-1d. The novel protein, designated ECE-1 sv, has an apparent molecular mass of 75 kDa; by using site-directed mutagenesis its start site was identified in a region common to all ECE-1 forms suggesting that ECE-1 b-d SV mRNAs are translated into the same protein. In agreement with the findings demonstrating common COOH terminus for ECE-1sv and ECE-1d, both exhibited a similar catalytic activity. However, immunofluorescence staining and differential centrifugation revealed a distinct intracellular localization for these two proteins. The presence of ECE-1sv in different cellular compartments than full-length forms of the enzyme may suggest a distinct physiological role for these proteins.

Research paper thumbnail of Endothelin-converting Enzyme-1, Abundance of Isoforms a-d and Identification of a Novel Alternatively Spliced Variant Lacking a Transmembrane Domain

Journal of Biological Chemistry, Dec 1, 2005

Endothelin-converting enzyme-1 (ECE-1) cleaves big endothelins, as well as bradykinin and ␤-amylo... more Endothelin-converting enzyme-1 (ECE-1) cleaves big endothelins, as well as bradykinin and ␤-amyloid peptide. Several isoforms of ECE-1 (a-d) have been identified to date; they differ only in their NH 2 terminus but share the catalytic domain located in the COOHterminal end. Using quantitative PCR, we found ECE-1d to be the most abundant type in several endothelial cells (EC) types. In addition to full-length ECE-1 forms we have identified novel, alternatively spliced mRNAs of ECE-1 b-d. These splice variants (SVs) lack exon 3, which codes for the transmembrane region and is present in full-length forms. SVs mRNA were highly expressed in EC derived from macro and microvascular beds but much less so in other, nonendothelial cells expressing ECE-1, which suggests that the splicing mechanism is cell-specific. Analyses of ECE-1d and its SV form in stably transfected HEK-293 cells revealed that both proteins were recognized by anti COOH-terminal ECE-1 antibodies, but anti NH 2-terminal antibodies only bound ECE-1d. The novel protein, designated ECE-1 sv, has an apparent molecular mass of 75 kDa; by using site-directed mutagenesis its start site was identified in a region common to all ECE-1 forms suggesting that ECE-1 b-d SV mRNAs are translated into the same protein. In agreement with the findings demonstrating common COOH terminus for ECE-1sv and ECE-1d, both exhibited a similar catalytic activity. However, immunofluorescence staining and differential centrifugation revealed a distinct intracellular localization for these two proteins. The presence of ECE-1sv in different cellular compartments than full-length forms of the enzyme may suggest a distinct physiological role for these proteins.

Research paper thumbnail of Characterization of endothelin-1 and nitric oxide generating systems in corpus luteum-derived endothelial cells

Reproduction, 2004

Endothelium-derived endothelin-1 (ET-1) and nitric oxide (NO) are pivotal regulators of corpus lu... more Endothelium-derived endothelin-1 (ET-1) and nitric oxide (NO) are pivotal regulators of corpus luteum (CL) function. To have a better insight into their synthesis and action, members of the ET system (ET-1, ET converting enzyme (ECE-1) isoforms a–d, ETAand ETBreceptors) along with NO synthase (NOS) isoforms – endothelial (e)NOS and inducible (i)NOS – were quantified in CL-derived endothelial cells (CLEC). The expression of these genes in microvascular CLEC, obtained by lectin-coated magnetic beads, was compared with cells removed from the luteal microenvironment and maintained in culture for different durations, and with endothelial cells (EC) derived from a large blood vessel (i.e. bovine aortic endothelial cells, BAEC). The profile of gene expression in the different EC types was determined by quantitative real-time PCR. Freshly isolated EC from mid-cycle CL exhibited high ET-1 receptor expression (both ETAand ETB), low ET-1 synthesizing ability (both prepro (pp) ET-1 and ECE-1), ...

Research paper thumbnail of Endothelin-converting Enzyme-1, Abundance of Isoforms a-d and Identification of a Novel Alternatively Spliced Variant Lacking a Transmembrane Domain

Journal of Biological Chemistry, 2005

Endothelin-converting enzyme-1 (ECE-1) cleaves big endothelins, as well as bradykinin and ␤-amylo... more Endothelin-converting enzyme-1 (ECE-1) cleaves big endothelins, as well as bradykinin and ␤-amyloid peptide. Several isoforms of ECE-1 (a-d) have been identified to date; they differ only in their NH 2 terminus but share the catalytic domain located in the COOHterminal end. Using quantitative PCR, we found ECE-1d to be the most abundant type in several endothelial cells (EC) types. In addition to full-length ECE-1 forms we have identified novel, alternatively spliced mRNAs of ECE-1 b-d. These splice variants (SVs) lack exon 3, which codes for the transmembrane region and is present in full-length forms. SVs mRNA were highly expressed in EC derived from macro and microvascular beds but much less so in other, nonendothelial cells expressing ECE-1, which suggests that the splicing mechanism is cell-specific. Analyses of ECE-1d and its SV form in stably transfected HEK-293 cells revealed that both proteins were recognized by anti COOH-terminal ECE-1 antibodies, but anti NH 2-terminal antibodies only bound ECE-1d. The novel protein, designated ECE-1 sv, has an apparent molecular mass of 75 kDa; by using site-directed mutagenesis its start site was identified in a region common to all ECE-1 forms suggesting that ECE-1 b-d SV mRNAs are translated into the same protein. In agreement with the findings demonstrating common COOH terminus for ECE-1sv and ECE-1d, both exhibited a similar catalytic activity. However, immunofluorescence staining and differential centrifugation revealed a distinct intracellular localization for these two proteins. The presence of ECE-1sv in different cellular compartments than full-length forms of the enzyme may suggest a distinct physiological role for these proteins.