Castronovo V, Claysmith A P, Barker K T, Cioce V, Krutzsch H C, Sobel M E
Tumor Invasion and Metastasis Section, National Cancer Institute, Bethesda, Maryland 20892.
Biochem Biophys Res Commun. 1991 May 31;177(1):177-83. doi: 10.1016/0006-291x(91)91965-f.
High affinity interactions between cells and laminin are mediated, at least in part, by the 67 kDa laminin receptor (67 LR). A 37 kDa nascent polypeptide (37 LRP), predicted by a full length cDNA clone and obtained by in vitro translation of hybrid-selected laminin receptor mRNA, has been immunologically identified in cancer cell extracts as the putative precursor of the 67 LR. In this study, we used affinity purified antibodies developed against cDNA-deduced 37 LRP synthetic peptides in pulse chase experiments and demonstrated a precursor-product relationship between the 37 LRP and the 67 LR. Immunoblot, pulse chase and immunofluorescence experiments showed that transient transfection of the full length 37 LRP cDNA clone induced a dramatic increase in the synthesis of the 37 LRP but not of the mature 67 LR. We propose that the 67 LR results from the association of two gene products: the 37 LRP and a polypeptide yet to be identified.
细胞与层粘连蛋白之间的高亲和力相互作用至少部分是由67 kDa层粘连蛋白受体（67 LR）介导的。通过全长cDNA克隆预测并通过杂交选择的层粘连蛋白受体mRNA的体外翻译获得的37 kDa新生多肽（37 LRP），已在癌细胞提取物中通过免疫鉴定为67 LR的推定前体。在本研究中，我们在脉冲追踪实验中使用了针对cDNA推导的37 LRP合成肽开发的亲和纯化抗体，并证明了37 LRP与67 LR之间的前体-产物关系。免疫印迹、脉冲追踪和免疫荧光实验表明，全长37 LRP cDNA克隆的瞬时转染导致37 LRP的合成显著增加，但成熟的67 LR没有增加。我们提出，67 LR是由两种基因产物结合产生的：37 LRP和一种有待鉴定的多肽。
