Glenney J R, Soppet D
Lucille P. Markey Cancer Center, Lexington, KY.
Proc Natl Acad Sci U S A. 1992 Nov 1;89(21):10517-21. doi: 10.1073/pnas.89.21.10517.
Caveolae are flask-shaped plasma membrane invaginations abundant in endothelium and muscle but may be present in all cells. They contain a filamentous coat material thought to be important in their structure and function. Recent studies have demonstrated that a 22-kDa protein (caveolin) phosphorylated on tyrosine in Rous sarcoma virus-transformed chicken fibroblasts is a component of the caveolae coat on the inner aspect of the membrane. We now report the deduced protein sequence of chicken caveolin derived from cDNA PCR products and genomic DNA clones. Caveolin is a unique protein of 178 amino acids and displays little sequence similarity to other proteins in the GenBank data base. Hydrophobicity predictions indicate an unusual 40-amino acid hydrophobic region near the C terminus that may be used to anchor the protein to the membrane. When chicken caveolin was expressed in mouse 3T3 cells and detected by immunofluorescence microscopy, the typical caveolae pattern was observed. This includes brightly fluorescent membrane patches in many cases concentrated at the margin of cells and in arrays. Caveolae may be distinct from other membrane domains due at least in part to caveolin.
小窝是烧瓶状的质膜内陷结构，在内皮细胞和肌肉细胞中大量存在，但也可能存在于所有细胞中。它们含有一种丝状包被物质，被认为对其结构和功能很重要。最近的研究表明，在劳氏肉瘤病毒转化的鸡成纤维细胞中，一种在酪氨酸上磷酸化的22 kDa蛋白（小窝蛋白）是膜内侧小窝包被的一个组成部分。我们现在报告从cDNA PCR产物和基因组DNA克隆推导得到的鸡小窝蛋白的蛋白质序列。小窝蛋白是一种由178个氨基酸组成的独特蛋白质，与GenBank数据库中的其他蛋白质几乎没有序列相似性。疏水性预测表明，在C末端附近有一个异常的40个氨基酸的疏水区域，可能用于将该蛋白质锚定在膜上。当鸡小窝蛋白在小鼠3T3细胞中表达并通过免疫荧光显微镜检测时，观察到了典型的小窝模式。这包括在许多情况下明亮荧光的膜斑，集中在细胞边缘并呈阵列状。小窝可能至少部分由于小窝蛋白而与其他膜结构域不同。
