Functional analysis of the profilaggrin N-terminal peptide: Identification of domains that regulate nuclear and cytoplasmic distribution
Functional analysis of the profilaggrin N-terminal peptide: Identification of domains that regulate nuclear and cytoplasmic distribution
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DOI：
10.1046/j.1523-1747.2002.01831.x
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发表时间：
2002-09-01
影响因子：
6.5
通讯作者：
Presland, RB
中科院分区：
文献类型：
--
作者：
Pearton, DJ;Dale, BA;Presland, RB
侧聚蛋白在表皮和其他层状上皮的分化颗粒层中表达，在那里它形成细胞质角化素颗粒的主要成分。它由两个不同的结构域组成，一个n端s100样Ca2+结合结构域包含两个ef -手和多个聚丝蛋白单位，这些聚丝蛋白单位聚集角质层中的角蛋白丝。在这里，我们报道了小鼠、人类和大鼠侧聚蛋白n端肽的结构-功能研究。所有物种的聚面蛋白n端肽均含有两个s100样ef -手，两部分核定位序列和蛋白转化酶裂解位点。人类和小鼠聚丝蛋白的核定位信号通过转染上皮细胞被证明是有效的，并且依赖于聚丝蛋白序列的缺失。人侧聚蛋白加工（游离）n端肽的核定位与正常人类皮肤和角化不全皮肤疾病的免疫定位结果一致，后者表现为颗粒状和/或角化层的核染色。小鼠聚丝蛋白n端蛋白水解过程分两步进行，首先释放含有聚丝蛋白序列的n端肽，最后释放28- 30kda的游离n端；当在转染细胞中表达时，这些肽分别具有细胞质和细胞核分布。n端加工可以在聚丝蛋白结构域的蛋白水解加工之前或同时发生。在表皮和转染细胞中，侧聚蛋白n端肽的核积累强烈表明，在表皮末端分化过程中，当游离的n端通过特异性蛋白水解从侧聚蛋白中释放出来时，侧聚蛋白n端具有钙依赖的核功能。
Profilaggrin is expressed in the differentiating granular layer of epidermis and other stratified epithelia, where it forms a major component of cytoplasmic keratohyalin granules. It consists of two distinct domains, an N-terminal S100-like Ca2+- binding domain containing two EF-hands and multiple filaggrin units that aggregate keratin filaments in the stratum corneum. Here, we report structure-function studies of the N-terminal peptide from mouse, human, and rat profilaggrin. The profilaggrin N-terminal peptides of all species contain two S100-like EF-hands, bipartite nuclear localization sequences, and proprotein convertase cleavage sites. The nuclear localization signals in human and mouse profilaggrin were shown to be functional by transfection of epithelial cells and depended on the absence of filaggrin sequences. The nuclear localization of the processed (free) N-terminal peptide of human profilaggrin is consistent with immunolocalization findings in normal human skin and in parakeratotic skin disorders, which exhibit nuclear staining of granular and/or cornified layers. The mouse profilaggrin N-terminus undergoes proteolytic processing in two steps, first releasing an N-terminal peptide containing some filaggrin sequence and finally the free N-terminus of 28-30 kDa; these peptides have cytoplasmic and nuclear distributions, respectively, when expressed in transfected cells. The N-terminal processing may occur prior to or simultaneously with the proteolytic processing of the polyfilaggrin domain. The nuclear accumulation of the profilaggrin N-terminal peptide in epidermis and in transfected cells strongly suggests a calcium-dependent nuclear function for the profilaggrin N-terminus during epidermal terminal differentiation when the free N-terminus is released from profilaggrin by specific proteolysis.