AN N-TERMINAL HYDROPHOBIC PEAK IS THE SORTING SIGNAL OF REGULATED SECRETORY PROTEINS
AN N-TERMINAL HYDROPHOBIC PEAK IS THE SORTING SIGNAL OF REGULATED SECRETORY PROTEINS
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DOI：
10.1016/0014-5793(95)00142-v
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发表时间：
1995-03-13
期刊：
影响因子：
3.5
通讯作者：
DARLING, DS
中科院分区：
文献类型：
--
作者：
GORR, SU;DARLING, DS
内分泌细胞和外分泌细胞各自含有调节的和组成性的分泌途径。在相同细胞类型中存在两种不同的分泌途径需要分选步骤以将分泌蛋白引导至正确的途径。据认为，受调节的分泌蛋白含有特定的分选信号。然而，该信号尚未被鉴定。氨基酸序列比较未揭示不同调节分泌蛋白之间的任何显著相似性，表明分选信号不由保守的一级序列组成。在本报告中，我们分析了预测的调节分泌蛋白的二级结构，并确定了一个N-末端疏水峰（NHP），该峰位于氨基酸9-26附近，与预测的α-螺旋重叠，并含有带电氨基酸残基，该信号存在于显示N-末端分选序列的调节分泌蛋白中，但它不存在于组成型分泌蛋白和分选序列不位于N-末端附近的蛋白中。看来NHP对于将许多分泌蛋白分选到受调节的分泌途径是必要的和充分的。
Endocrine and exocrine cells each contain a regulated and constitutive secretory pathway, The presence of two distinct secretory pathways in the same cell type requires a sorting step to direct secretory proteins to the correct pathway. It is thought that regulated secretory proteins contain a specific sorting signal. However, this signal has not been identified, Amino acid sequence comparisons have not revealed any significant similarity between different regulated secretory proteins, suggesting that the sorting signal does not consist of a conserved primary sequence. In the present report, we have analyzed the predicted secondary structures of regulated secretory proteins and identified an N-terminal hydrophobic peak (NHP) which is located approximately from amino acids 9-26, overlaps with a predicted alpha-helix and contains charged amino acid residues, This signal is present in regulated secretory proteins that exhibit an N-terminal sorting sequence, but it is absent from constitutively secreted proteins and proteins where the sorting sequence is not located near the N-terminus. It appears that the NHP is both necessary and sufficient for sorting of many secretory proteins to the regulated secretory pathway.