Abstract
The extracellular matrix (ECM) has been shown to play an important role in development and tissue-specific gene expression, yet the mechanism by which genes receive signals from the ECM is poorly understood. The aboral ectoderm-specific LpS1-α and -β genes of Lytechinus pictus, members of the Spec gene family, provide an excellent model system to study ECM-mediated gene regulation. Disruption of the ECM by preventing collagen deposition using the lathrytic agent β-aminopropionitrile (BAPN) inhibits LpS1 gene transcription. LpS1 transcription resumes after removal of BAPN and subsequent collagen reformation. Using a chloramphenicol acetyltransferase (CAT) reporter gene assay, we show that a 125 bp region of the LpS1-β promoter from -108 to +17 contains an ECM response element (ECM RE). Insertion of the 125 bp region into the promoter of the metallothionein gene of L. pictus, a gene unaffected by ECM disruption, caused the fused promoter to become ECM dependent. As with the endogenous LpS1 genes, CAT activity directed by the fused LpS1-β promoter resumed in embryos recovered from ECM disruption. A mutation in a cis-acting element called the proximal G-string, which lies in the 125 bp region, caused CAT activity levels in ECM-disrupted embryos to equal that of the wild-type LpS1-β promoter in ECM-intact embryos. These results suggest that the intact ECM normally transmits signals to inhibit repressor activity at the proximal G-string in aboral ectoderm cells. Consistent with these results were our findings which showed that in addition to expression in the aboral ectoderm, the proximal G-string mutation caused expression of the CAT gene in oral ectoderm cells. These studies suggested that the proximal G-string serves as a binding site for negative regulation of the LpS1 genes in oral ectoderm during development. We also examined trans-acting factors binding the proximal G-string following ECM disruption. Band shift gels revealed a predominant set of slower migrating nuclear proteins from ECM-disrupted embryos which bound the proximal G-string. This work suggested that ECM disruption initiates signaling that induces a repressor to bind the ECM RE and/or modifies ECM RE binding proteins, which in turn represses LpS1 gene activity.
| Original language | English |
|---|---|
| Pages (from-to) | 3175-3182 |
| Number of pages | 8 |
| Journal | Nucleic Acids Research |
| Volume | 25 |
| Issue number | 15 |
| DOIs | |
| State | Published - Aug 1 1997 |
| Externally published | Yes |
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All Science Journal Classification (ASJC) codes
- Genetics
Cite this
An extracellular matrix response element in the promoter of the LpS1 genes of the sea urchin Lytechinus pictus. / Seid, Christopher A.; Ramachandran, Ravi K.; George, Jenny M.; Govindarajan, Venkatesh; González-Rimbau, Maria F.; Flytzanis, Constantin N.; Tomlinson, Craig R.
In: Nucleic Acids Research, Vol. 25, No. 15, 01.08.1997, p. 3175-3182.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - An extracellular matrix response element in the promoter of the LpS1 genes of the sea urchin Lytechinus pictus
AU - Seid, Christopher A.
AU - Ramachandran, Ravi K.
AU - George, Jenny M.
AU - Govindarajan, Venkatesh
AU - González-Rimbau, Maria F.
AU - Flytzanis, Constantin N.
AU - Tomlinson, Craig R.
PY - 1997/8/1
Y1 - 1997/8/1
N2 - The extracellular matrix (ECM) has been shown to play an important role in development and tissue-specific gene expression, yet the mechanism by which genes receive signals from the ECM is poorly understood. The aboral ectoderm-specific LpS1-α and -β genes of Lytechinus pictus, members of the Spec gene family, provide an excellent model system to study ECM-mediated gene regulation. Disruption of the ECM by preventing collagen deposition using the lathrytic agent β-aminopropionitrile (BAPN) inhibits LpS1 gene transcription. LpS1 transcription resumes after removal of BAPN and subsequent collagen reformation. Using a chloramphenicol acetyltransferase (CAT) reporter gene assay, we show that a 125 bp region of the LpS1-β promoter from -108 to +17 contains an ECM response element (ECM RE). Insertion of the 125 bp region into the promoter of the metallothionein gene of L. pictus, a gene unaffected by ECM disruption, caused the fused promoter to become ECM dependent. As with the endogenous LpS1 genes, CAT activity directed by the fused LpS1-β promoter resumed in embryos recovered from ECM disruption. A mutation in a cis-acting element called the proximal G-string, which lies in the 125 bp region, caused CAT activity levels in ECM-disrupted embryos to equal that of the wild-type LpS1-β promoter in ECM-intact embryos. These results suggest that the intact ECM normally transmits signals to inhibit repressor activity at the proximal G-string in aboral ectoderm cells. Consistent with these results were our findings which showed that in addition to expression in the aboral ectoderm, the proximal G-string mutation caused expression of the CAT gene in oral ectoderm cells. These studies suggested that the proximal G-string serves as a binding site for negative regulation of the LpS1 genes in oral ectoderm during development. We also examined trans-acting factors binding the proximal G-string following ECM disruption. Band shift gels revealed a predominant set of slower migrating nuclear proteins from ECM-disrupted embryos which bound the proximal G-string. This work suggested that ECM disruption initiates signaling that induces a repressor to bind the ECM RE and/or modifies ECM RE binding proteins, which in turn represses LpS1 gene activity.
AB - The extracellular matrix (ECM) has been shown to play an important role in development and tissue-specific gene expression, yet the mechanism by which genes receive signals from the ECM is poorly understood. The aboral ectoderm-specific LpS1-α and -β genes of Lytechinus pictus, members of the Spec gene family, provide an excellent model system to study ECM-mediated gene regulation. Disruption of the ECM by preventing collagen deposition using the lathrytic agent β-aminopropionitrile (BAPN) inhibits LpS1 gene transcription. LpS1 transcription resumes after removal of BAPN and subsequent collagen reformation. Using a chloramphenicol acetyltransferase (CAT) reporter gene assay, we show that a 125 bp region of the LpS1-β promoter from -108 to +17 contains an ECM response element (ECM RE). Insertion of the 125 bp region into the promoter of the metallothionein gene of L. pictus, a gene unaffected by ECM disruption, caused the fused promoter to become ECM dependent. As with the endogenous LpS1 genes, CAT activity directed by the fused LpS1-β promoter resumed in embryos recovered from ECM disruption. A mutation in a cis-acting element called the proximal G-string, which lies in the 125 bp region, caused CAT activity levels in ECM-disrupted embryos to equal that of the wild-type LpS1-β promoter in ECM-intact embryos. These results suggest that the intact ECM normally transmits signals to inhibit repressor activity at the proximal G-string in aboral ectoderm cells. Consistent with these results were our findings which showed that in addition to expression in the aboral ectoderm, the proximal G-string mutation caused expression of the CAT gene in oral ectoderm cells. These studies suggested that the proximal G-string serves as a binding site for negative regulation of the LpS1 genes in oral ectoderm during development. We also examined trans-acting factors binding the proximal G-string following ECM disruption. Band shift gels revealed a predominant set of slower migrating nuclear proteins from ECM-disrupted embryos which bound the proximal G-string. This work suggested that ECM disruption initiates signaling that induces a repressor to bind the ECM RE and/or modifies ECM RE binding proteins, which in turn represses LpS1 gene activity.
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U2 - 10.1093/nar/25.15.3175
DO - 10.1093/nar/25.15.3175
M3 - Article
VL - 25
SP - 3175
EP - 3182
JO - Nucleic Acids Research
JF - Nucleic Acids Research
SN - 0305-1048
IS - 15
ER -