GLYCAN MEDIATED REGULATION OF CD44 FUNCTION

描述(申请人描述)：大多数人类癌症死亡病例 是由于转移，这一过程在分子水平上知之甚少 和细胞水平。在多步骤的转移过程中，人们可以预料到 细胞黏附分子的重要作用。CD44，一种细胞表面 透明质酸(HA)受体在细胞黏附中的作用 迁移和细胞激活被牵连到了 转移。CD44具有调节其配体亲和力的特性。 糖基化在调节CD44介导的透明质酸结合中的作用 因此将被审查。这项研究与候选人的研究是一致的 长期目标是阐明足够详细的机制，通过它 糖基化调节细胞黏附分子功能以实现调节 这一机制作为对转移的干预。初步研究 已经确定了影响内源性的寡糖结构 CD44的HA结合特性。本提案的目的是确定 结构受到生物调节，并阐明酶的基础 对于功能调节来说，I是重要的糖链结构。之后 关键糖基转移酶的鉴定，其作用机制 作为整合细胞行为的一部分，细胞调节CD44糖基化 将会被定义。要研究的机制包括合成的 糖基转移酶表达、糖基转移酶磷酸化、CD44 选择性的RNA剪接和相互作用的糖基转移酶。CD44 寡糖结构将通过糖苷酶消化和 糖基转移酶调节。固有的CD44 HA亲和力将是 采用亲和毛细管电泳法测定。结构/功能 将会得出相关的结论。CD44糖基化和CD44的生理性改变 透明质酸亲和力将在细胞激活时进行测试。对以下方面的影响 糖基转移酶调控CD44 HA亲和力的转移 调制将使用体内模型来确定。这项提议将 作为制定定义法规的一般方法的基础 糖基化在细胞-细胞和细胞-基质黏附中的作用。

DESCRIPTION (Applicant's Description): The majority of human cancer deaths are due to metastasis, a process that is poorly understood at the molecular and cellular levels. In the multistep process of metastasis one expects significant roles for cell adhesion molecules. CD44, a cell surface receptor for hyaluronan (HA) that functions in cell adhesion, cell migration, and cell activation, has been implicated in the process of metastasis. CD44 has the property of regulated affinity for its ligand. The role of glycosylation in regulating CD44-mediated hyaluronan binding will therefore be examined. This study is consistent with the candidate's long-term objective of elucidating enough detail of the mechanism by which glycosylation regulates cell adhesion molecule function to enable modulation of this mechanism as an intervention f o r metastasis. Preliminary studies have identified oligosaccharide structures which impact the intrinsic HA-binding properties of CD44. The present proposal aims to determine which structures are biologically regulated and to elucidate the enzymatic basis for regulation of the functionally i m portant glycan structure. After identification of the key glycosyltransferase, the mechanism employed by the cell to regulate CD44 glycosylation as part of an integrated cell behavior will be defined. Mechanisms to be examined include synthetic glycosyltransferase expression, glycosyltransferase phosphorylation, CD44 alternative RNA splicing, and interacting glycosyltransferases. CD44 oligosaccharide structure will be c h a n ged by glycosidase digestion and glycosyltransferase modulation. I n t rinsic CD44 HA-affinity will be determined by affinity capillary e l e ctrophoresis. Structure/function correlations will be drawn. A physiologic change in CD44 glycosylation and hyaluronan-affinity will be tested upon cellular activation. The effects on metastasis of manipulating CD44 HA-affinity by glycosyltransferase modulation will be determined using an in vivo model. This proposal will serve as a basis to develop a general approach to defining the regulatory role of glycosylation in cell-cell and cell-matrix adhesion.