Abstract:
zDHHC S-acyltransferases are enzymes catalyzing protein S-acylation, a common post-translational modification on proteins frequently affecting their membrane targeting and trafficking. The ankyrin repeat (AR) domain of zDHHC17 (HIP14) and zDHHC13 (HIP14L) S-acyltransferases, which is involved in both substrate recruitment and S-acylation-independent functions, was recently shown to bind at least six proteins, by specific recognition of a consensus sequence in them. To further refine the rules governing binding to the AR of zDHHC17, we employed peptide arrays based on zDHHC AR-binding motif (zDABM) sequences of synaptosomal-associated protein 25 (SNAP25) and cysteine string protein α (CSPα). Quantitative comparisons of the binding preferences of 400 peptides allowed us to construct a position-specific scoring matrix (PSSM) for zDHHC17 AR binding, with which we predicted and subsequently validated many putative zDHHC17 interactors. We identified 95 human zDABM sequences with unexpected versatility in amino acid usage; these sequences were distributed among 90 proteins, of which 62 have not been previously implicated in zDHHC17/13 binding. These zDABM-containing proteins included all family members of the SNAP25, sprouty, cornifelin, ankyrin, and SLAIN-motif containing families; seven endogenous Gag polyproteins sharing the same binding sequence; and several proteins involved in cytoskeletal organization, cell communication, and regulation of signaling. A dozen of the zDABM-containing proteins had more than one zDABM sequence, whereas isoform-specific binding to the AR of zDHHC17 was identified for the Ena/VASP-like protein. The large number of zDABM sequences within the human proteome suggests that zDHHC17 may be an interaction hub regulating many cellular processes.
摘要:
zDHHCS-酰基转移酶是催化蛋白质S-酰化的酶,蛋白质上常见的翻译后修饰,经常影响其膜靶向和运输。zDHHC17(HIP14)和zDHHC13(HIP14L)S-酰基转移酶的锚蛋白重复(AR)结构域,它涉及底物募集和S-酰化无关的功能,最近被证明可以结合至少六种蛋白质,通过特定识别它们中的共有序列。为了进一步完善控制与zDHHC17的AR结合的规则,我们采用了基于突触体相关蛋白25(SNAP25)和半胱氨酸串蛋白α(CSPα)的zDHHCAR结合基序(zDABM)序列的肽阵列。400肽结合偏好的定量比较使我们能够构建zDHHC17AR结合的位置特异性评分矩阵(PSSM),我们预测并随后验证了许多推定的zDHHC17相互作用物。我们鉴定了95个人类zDABM序列,在氨基酸使用方面具有意想不到的多功能性;这些序列分布在90种蛋白质中,其中62个以前没有与zDHHC17/13结合有关。这些含zDABM的蛋白质包括SNAP25的所有家族成员,Cornifelin,Ankyrin,和含有SLAIN基序的家族;七个内源性Gag多蛋白共享相同的结合序列;以及几种参与细胞骨架组织的蛋白质,细胞通讯,和信号的调节。十几种含有zDABM的蛋白质有一个以上的zDABM序列,而与ZDHHC17的AR的同工型特异性结合被鉴定为Ena/VASP样蛋白。人类蛋白质组中大量的zDABM序列表明zDHHC17可能是调节许多细胞过程的相互作用中枢。