The endoplasmic reticulum protein Jagunal (JAGN1) was first identified as a requirement for Drosophila melanogaster oocyte development. Subsequent studies in human patients linked mutations in JAGN1 to Severe Congenital Neutropenia (SCN), as well as a broad range of additional symptoms, suggesting that JAGN1 function is required in many tissues. Moreover, JAGN1 orthologues are found throughout animal and plant phylogeny, suggesting that JAGN1 supports fundamental cellular processes not restricted to egg development or neutrophil function. JAGN1 lacks sequence similarity or recognizable domains other than a COPI-binding motif, and its cellular function is currently unknown. JAGN1 shares a tetra-spanning membrane topology with two families of known cargo transporters: the tetraspanins and the Erv proteins. Herein, we discuss the similarities between JAGN1, tetraspanins and Ervs, and based on those suggest a role for JAGN1 in facilitating the traffic of cell-restricted and ubiquitously expressed proteins at the ER-Golgi interface.

中文翻译：

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JAGN1，四跨膜蛋白和 Erv 蛋白：常见的拓扑结构是否表明货物分拣中的常见功能？

内质网蛋白 Jagunal (JAGN1) 首次被确定为黑腹果蝇卵母细胞发育的必要条件。随后对人类患者的研究将 JAGN1 的突变与严重的先天性中性粒细胞减少症 (SCN) 以及广泛的其他症状联系起来，这表明在许多组织中都需要 JAGN1 功能。此外，JAGN1 直系同源物存在于整个动植物系统发育中，这表明 JAGN1 支持基本的细胞过程，不仅限于卵子发育或中性粒细胞功能。JAGN1 缺乏序列相似性或除 COPI 结合基序外的可识别域，其细胞功能目前未知。JAGN1 与两个已知的货物转运蛋白家族共享四跨膜拓扑结构：四跨膜蛋白和 Erv 蛋白。在此处，