Cleavage of urokinase receptor regulates its interaction with integrins in thyroid cells

FEBS Letters

Montuori, Nunzia²  Rossi, Guido²  Ragno, Pia¹ 

[1] Centro di Endocrinologia ed Oncologia Sperimentale (CEOS), Consiglio Nazionale delle Ricerche, via Pansini 5, I-80131 Naples, Italy;Dipartimento di Biologia e Patologia Cellulare e Molecolare, Università di Napoli, via Pansini 5, I-80131 Naples, Italy

关键词: Urokinase;    Urokinase receptor;    β-Integrin;    Thyroid;   

DOI  :  10.1016/S0014-5793(99)01314-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The urokinase-type plasminogen activator uPA-R can regulate integrin functions by associating with several types of β-subunit. We have recently shown that normal thyroid TAD-2 cells express both a native and a cleaved form of uPA-R which lacks the binding domain for uPA. We found this cleaved form to be present in reduced amounts in papillary and follicular thyroid carcinoma cells and completely absent in cells derived from an anaplastic thyroid carcinoma (ARO). We now report that in normal thyroid cells the intact form of uPA-R strongly associates with β-1 integrins, whereas its cleaved form does not. uPA-R expressed by ARO cells shows a stronger resistance to the cleavage mediated by uPA, plasmin and chymotrypsin than does uPA-R expressed by normal thyroid cells. This resistance to cleavage correlates with the higher level of glycosylation of uPA-R of ARO cells as compared to that of cleavable uPA-R of normal thyroid cells. These results suggest that uPA-R cleavage, which occurs in several cell types, represents a mechanism regulating the interactions of uPA-R with integrins and, possibly, the subsequent integrin-mediated cell adhesion. Moreover we hypothesize that glycosylation regulates uPA-R cleavage and, indirectly, its interaction with integrins.

【 授权许可】

Unknown