An exciting prospect will be to elucidate the precise mechanism of adherens junction destabilization by cleaved Arm, as the truncated protein retains binding sites for both E-cadherin and α-catenin. One model proposed by Kessler and Muller [9] is that the amino-terminal truncation of Arm may inhibit its association with E-cadherin, as shown for β-catenin in mammals. However, Arm cleavage does not seem to completely abolish adherens junction formation, as suggested by an experiment in which an arm mutant can be at least partially rescued by amino-terminally truncated Arm. An alternative is that modifications of other compo- nents of the adherens junction complex (cleavage of E-cadherin has been reported in mammals [10]) contribute to the sequential dissociation of the junction. β-Catenin was already a known substrate of caspase-3 in mammals, and its cleavage there coincides with the destabi- lization of adherens junctions. However, the physiological significance of this cleavage remains to be tested, and it is not yet known whether the separation of the adherens junctions is progressive, as it is in Drosophila (Figure 1). It has been shown in mammalian cells that the truncated β-catenin loses its ability to bind α-catenin, thus releasing α-catenin from the junction and leading to the retraction of the microfilament system [11]. However, these data are controversial [12], and loss of α-catenin-binding capacity by cleaved β-catenin might depend on the cell type. Also,
An exciting prospect will be to elucidate the precise mechanism of adherens junction destabilization by cleaved Arm, as the truncated protein retains binding sites for both E-cadherin and α-catenin. One model proposed by Kessler and Muller [9] is that the amino-terminal truncation of Arm may inhibit its association with E-cadherin, as shown for β-catenin in mammals. However,แขนตัวดูเหมือนไม่สมบูรณ์ยกเลิกการ adherens แยกเป็นแนะนำโดยการทดลองที่แขนที่กลายพันธุ์สามารถอย่างน้อยบางส่วนได้ อะมิโน ยังตัดแขน An alternative is that modifications of other compo- nents of the adherens junction complex (cleavage of E-cadherin has been reported in mammals [10]) contribute to the sequential dissociation of the junction. β-Catenin was already a known substrate of caspase-3 in mammals, and its cleavage there coincides with the destabi- lization of adherens junctions. However,ความสำคัญทางสรีรวิทยาของความแตกแยกนี้ยังคงถูกทดสอบ และยังไม่เป็นที่รู้จักกันว่า การแยกของ adherens junctions ก้าวหน้าในขณะที่มันอยู่ในแมลงหวี่ ( รูปที่ 1 ) มันได้ถูกแสดงในเซลล์สัตว์เลี้ยงลูกด้วยนมที่ตัดทอนบีตา - catenin สูญเสียความสามารถในการผูก catenin แอลฟา , thus releasing α-catenin from the junction and leading to the retraction of the microfilament system [11]. However, these data are controversial [12], and loss of α-catenin-binding capacity by cleaved β-catenin might depend on the cell type. Also,
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