Limits...
Cadherin-mediated cell sorting not determined by binding or adhesion specificity.

Niessen CM, Gumbiner BM - J. Cell Biol. (2002)

Bottom Line: None of the different cadherin-expressing cells exhibited any adhesive specificity toward either of the two purified cadherin substrates, even though these cadherins differ considerably in their primary sequence.However, this lack of adhesive specificity did not determine whether different cadherin-expressing cells would sort from each other, and the tendency to sort was not predictable by the extent of sequence diversity in their extracellular domains.These results show that cadherins are far more promiscuous in their adhesive-binding capacity than had been expected and that the ability to sort out must be determined by mechanisms other than simple adhesive-binding specificity.

View Article: PubMed Central - PubMed

Affiliation: Cellular Biochemistry and Biophysics Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA.

ABSTRACT
Cadherin adhesion molecules play important roles in the establishment of tissue boundaries. Cells expressing different cadherins sort out from each other in cell aggregation assays. To determine the contribution of cadherin binding and adhesion specificity to the sorting process, we examined the adhesion of cells to different purified cadherin proteins. Chinese hamster ovary cell lines expressing one of four different cadherins were allowed to bind to the purified cadherin extracellular domains of either human E-cadherin or Xenopus C-cadherin, and the specificity of adhesion was compared with cell-sorting assays. None of the different cadherin-expressing cells exhibited any adhesive specificity toward either of the two purified cadherin substrates, even though these cadherins differ considerably in their primary sequence. In addition, all cells exhibited similar strengthening of adhesion on both substrates. However, this lack of adhesive specificity did not determine whether different cadherin-expressing cells would sort from each other, and the tendency to sort was not predictable by the extent of sequence diversity in their extracellular domains. These results show that cadherins are far more promiscuous in their adhesive-binding capacity than had been expected and that the ability to sort out must be determined by mechanisms other than simple adhesive-binding specificity.

Show MeSH

Related in: MedlinePlus

Xenopus blastomeres adhere similarly well to both CEC1–5Fc and HEEC1–5Fc proteins. Blastomeres isolated from Xenopus animal cap tissue explants were allowed to adhere to different amounts of HEEC1–5Fc, CEC1–5Fc, or BSA. The results shown are the average of four independent experiments. Black bars, HEEC1–5Fc protein; white bars, CEC1–5Fc protein. Note that adherence of blastomeres to BSA alone is negligible, and therefore does not appear in the graph.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2199232&req=5

fig3: Xenopus blastomeres adhere similarly well to both CEC1–5Fc and HEEC1–5Fc proteins. Blastomeres isolated from Xenopus animal cap tissue explants were allowed to adhere to different amounts of HEEC1–5Fc, CEC1–5Fc, or BSA. The results shown are the average of four independent experiments. Black bars, HEEC1–5Fc protein; white bars, CEC1–5Fc protein. Note that adherence of blastomeres to BSA alone is negligible, and therefore does not appear in the graph.

Mentions: CHO cells normally do not express any significant amount of cadherin. The observed heterotypic cadherin interaction could potentially be attributed to the nonphysiological expression of cadherins in CHO cells. Xenopus blastomere cells, isolated from animal cap tissue explants, express C-cadherin as their major cadherin, and were used to test if physiological cadherin expression would also result in heterophilic adhesion. Using HEEC1–5Fc and CEC1–5Fc as substrates, blastomeres were allowed to bind for a period, after which they were subjected to detachment forces by rotating the dish shortly. Adhesion was measured by counting attached blastomeres before and after rotation (Zhong et al., 1999). Blastomeres adhere just about as well to HEEC1–5Fc as to CEC1–5Fc, and this adhesion showed a similar concentration dependency for both substrates (Fig. 3) . Blastomeres did not adhere to BSA (Fig. 3) or either cadherin substrate in the presence of EDTA (unpublished data). Thus, when expressed under normal physiological circumstances, C-cadherin still mediates a strong heterotypic interaction with human E-cadherin protein.


Cadherin-mediated cell sorting not determined by binding or adhesion specificity.

Niessen CM, Gumbiner BM - J. Cell Biol. (2002)

Xenopus blastomeres adhere similarly well to both CEC1–5Fc and HEEC1–5Fc proteins. Blastomeres isolated from Xenopus animal cap tissue explants were allowed to adhere to different amounts of HEEC1–5Fc, CEC1–5Fc, or BSA. The results shown are the average of four independent experiments. Black bars, HEEC1–5Fc protein; white bars, CEC1–5Fc protein. Note that adherence of blastomeres to BSA alone is negligible, and therefore does not appear in the graph.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2199232&req=5

fig3: Xenopus blastomeres adhere similarly well to both CEC1–5Fc and HEEC1–5Fc proteins. Blastomeres isolated from Xenopus animal cap tissue explants were allowed to adhere to different amounts of HEEC1–5Fc, CEC1–5Fc, or BSA. The results shown are the average of four independent experiments. Black bars, HEEC1–5Fc protein; white bars, CEC1–5Fc protein. Note that adherence of blastomeres to BSA alone is negligible, and therefore does not appear in the graph.
Mentions: CHO cells normally do not express any significant amount of cadherin. The observed heterotypic cadherin interaction could potentially be attributed to the nonphysiological expression of cadherins in CHO cells. Xenopus blastomere cells, isolated from animal cap tissue explants, express C-cadherin as their major cadherin, and were used to test if physiological cadherin expression would also result in heterophilic adhesion. Using HEEC1–5Fc and CEC1–5Fc as substrates, blastomeres were allowed to bind for a period, after which they were subjected to detachment forces by rotating the dish shortly. Adhesion was measured by counting attached blastomeres before and after rotation (Zhong et al., 1999). Blastomeres adhere just about as well to HEEC1–5Fc as to CEC1–5Fc, and this adhesion showed a similar concentration dependency for both substrates (Fig. 3) . Blastomeres did not adhere to BSA (Fig. 3) or either cadherin substrate in the presence of EDTA (unpublished data). Thus, when expressed under normal physiological circumstances, C-cadherin still mediates a strong heterotypic interaction with human E-cadherin protein.

Bottom Line: None of the different cadherin-expressing cells exhibited any adhesive specificity toward either of the two purified cadherin substrates, even though these cadherins differ considerably in their primary sequence.However, this lack of adhesive specificity did not determine whether different cadherin-expressing cells would sort from each other, and the tendency to sort was not predictable by the extent of sequence diversity in their extracellular domains.These results show that cadherins are far more promiscuous in their adhesive-binding capacity than had been expected and that the ability to sort out must be determined by mechanisms other than simple adhesive-binding specificity.

View Article: PubMed Central - PubMed

Affiliation: Cellular Biochemistry and Biophysics Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA.

ABSTRACT
Cadherin adhesion molecules play important roles in the establishment of tissue boundaries. Cells expressing different cadherins sort out from each other in cell aggregation assays. To determine the contribution of cadherin binding and adhesion specificity to the sorting process, we examined the adhesion of cells to different purified cadherin proteins. Chinese hamster ovary cell lines expressing one of four different cadherins were allowed to bind to the purified cadherin extracellular domains of either human E-cadherin or Xenopus C-cadherin, and the specificity of adhesion was compared with cell-sorting assays. None of the different cadherin-expressing cells exhibited any adhesive specificity toward either of the two purified cadherin substrates, even though these cadherins differ considerably in their primary sequence. In addition, all cells exhibited similar strengthening of adhesion on both substrates. However, this lack of adhesive specificity did not determine whether different cadherin-expressing cells would sort from each other, and the tendency to sort was not predictable by the extent of sequence diversity in their extracellular domains. These results show that cadherins are far more promiscuous in their adhesive-binding capacity than had been expected and that the ability to sort out must be determined by mechanisms other than simple adhesive-binding specificity.

Show MeSH
Related in: MedlinePlus