Damien C, Robberecht P, Hooghe R, De Neef P, Christophe J
Department of Biochemistry and Nutrition, Medical School, Université Libre de Bruxelles, Brussels, Belgium.
Peptides. 1989 Sep-Oct;10(5):1075-9. doi: 10.1016/0196-9781(89)90192-7.
We examined the cultured mouse melanoma cell line B16 (clone F1) and its wheat germ agglutinin-resistant variant Wa4 that suffers from abnormal protein glycosylation (a high fucose:sialic acid ratio in glycoproteins). In both cell lines the adenylate cyclase system was endowed with a functional guanine nucleotide binding protein Gs and was efficiently coupled to alpha-MSH receptors. In the B16 cell line F1 studied we also observed an efficient stimulation of adenylate cyclase activity by helodermin, VIP and the VIP analogue [acetyl-His1]VIP, and also by PGE1. In membranes from the lectin-resistant variant Wa4, the stimulations by VIP-like peptides and by PGE1 were reduced by 60% and 50%, respectively, while the stimulation by alpha-MSH remained normal. As other components of the adenylate cyclase system (Gs site, catalytical unit) appeared unchanged in the Wa4 variant, we conclude that impaired glycosylation essentially affected the number of both VIP-like peptide receptors and PGE1 receptors.
我们研究了培养的小鼠黑色素瘤细胞系B16（克隆F1）及其对麦胚凝集素耐药的变体Wa4，该变体存在异常的蛋白质糖基化（糖蛋白中岩藻糖与唾液酸的比例较高）。在这两种细胞系中，腺苷酸环化酶系统都具有功能性鸟嘌呤核苷酸结合蛋白Gs，并能有效地与α-促黑素（α-MSH）受体偶联。在我们研究的B16细胞系F1中，我们还观察到蛙皮素、血管活性肠肽（VIP）及其类似物[乙酰组氨酸1]VIP以及前列腺素E1（PGE1）对腺苷酸环化酶活性有有效的刺激作用。在对凝集素耐药的变体Wa4的细胞膜中，VIP样肽和PGE1的刺激作用分别降低了60%和50%，而α-MSH的刺激作用保持正常。由于腺苷酸环化酶系统的其他成分（Gs位点、催化单位）在Wa4变体中似乎没有变化，我们得出结论，糖基化受损主要影响了VIP样肽受体和PGE1受体的数量。
