Most cells in multicellular organisms are somehow asymmetric, polarized: maintaining separate membrane domains. Typical examples are the epithelial cells (apical-basal polarization), neurons (dendritic-axonal domains), or migratory cells (with a leading and a trailing edge). Here we present the most comprehensive database containing experimentally verified mammalian proteins that display polarized sorting or secretion, focusing at epithelial polarity. In addition to the source cells or tissues, homology-based inferences and transmembrane topology (if applicable) are all provided. PolarProtDb also offers a detailed interface displaying all information that may be relevant for trafficking: including post-translational modifications (glycosylations and phosphorylations), known or predicted short linear motifs conserved across orthologs, as well as potential interaction partners. Data on polarized sorting has so far been scattered across myriads of publications, hence difficult to access. This information can help researchers in several areas, such as scanning for potential entry points of viral agents like COVID-19. PolarProtDb shall be a useful resource to design future experiments as well as for comparative analyses. The database is available at http://polarprotdb.enzim.hu.

多细胞生物中的大多数细胞都以某种方式不对称，极化：维持独立的膜结构域。典型的例子是上皮细胞（顶基极极化），神经元（树突状轴突结构域）或迁移细胞（具有前缘和后缘）。在这里，我们提供了最全面的数据库，其中包含经过实验验证的哺乳动物蛋白质，这些蛋白质表现出极化的分类或分泌，着重于上皮极性。除了源细胞或组织，还提供了基于同源性的推论和跨膜拓扑（如果适用）。PolarProtDb还提供了详细的界面，显示了可能与贩运有关的所有信息：包括翻译后修饰（糖基化和磷酸化），直系同源基因中保守的已知或预测的短线性基序，以及潜在的互动合作伙伴。迄今为止，有关极化分类的数据分散在无数出版物中，因此很难获得。这些信息可以在多个领域为研究人员提供帮助，例如扫描诸如COVID-19之类的病毒制剂的潜在进入点。PolarProtDb将是设计未来实验以及进行比较分析的有用资源。该数据库位于http://polarprotdb.enzim.hu。