Berger S J, Resing K A, Taylor T C, Melançon P
Department of Chemistry and Biochemistry, University of Colorado at Boulder 80309-0215, USA.
Biochem J. 1995 Oct 1;311 ( Pt 1)(Pt 1):125-32. doi: 10.1042/bj3110125.
The two proteins from bovine brain previously shown to be required for the guanosine 5'-[gamma-thio]triphosphate-dependent inhibition of a well-characterized intra-Golgi transport assay, termed GGBF and GGBF, have been definitively identified as members of the ADP-ribosylation factor (ARF) family by electrospray MS analysis of the intact proteins, and of their tryptic fragments. Extensive protein-sequence information obtained from this analysis identified GGBF and GGBF as bovine ARF1 and ARF3 respectively. The sequence of bovine ARF3, which had not previously been determined, appears identical to that predicted from the rat and human ARF3 cDNAs. Further analysis of the N-terminal tryptic fragments of both bovine ARFs demonstrates N-terminal acylation solely with the C14:0 fatty acid (myristate). This finding establishes that the previously reported specific-activity difference between ARF1 and ARF3 in the intra-Golgi transport assay is not due to lipid heterogeneity at the N-terminus. This finding also indicates that the heterogeneity of N-terminal fatty-acyl groups previously observed on other myristoylated proteins is not universal.
先前已证明，在一种特征明确的高尔基体内转运分析中，牛脑来源的两种蛋白质是鸟苷5'-[γ-硫代]三磷酸依赖性抑制所必需的，分别称为GGBF和GGBF。通过对完整蛋白质及其胰蛋白酶片段进行电喷雾质谱分析，已明确将这两种蛋白质鉴定为ADP-核糖基化因子（ARF）家族的成员。从该分析中获得的大量蛋白质序列信息分别将GGBF和GGBF鉴定为牛ARF1和ARF3。先前未确定的牛ARF3序列，似乎与从大鼠和人类ARF3 cDNA预测的序列相同。对两种牛ARF的N端胰蛋白酶片段的进一步分析表明，N端仅被C14:0脂肪酸（肉豆蔻酸）酰化。这一发现表明，先前报道的在高尔基体内转运分析中ARF1和ARF3之间的比活性差异，并非由于N端的脂质异质性。这一发现还表明，先前在其他肉豆蔻酰化蛋白质上观察到的N端脂肪酰基的异质性并非普遍存在。
