Pannexin 1 (PANX1) is a glycoprotein that forms large pore channels capable of passing ions and metabolites such as ATP for cellular communication. PANX1 has been implicated in many diseases including breast cancer and melanoma, where inhibition or deletion of PANX1 reduced the tumorigenic and metastatic properties of the cancer cells. We interrogated the effect of single amino acid changes in various PANX1 domains, using naturally occurring variants reported in cancer patient tumors. We found that a previously reported variant (Q5H), is present in cancer cells, but was not different from the wildtype (Q5) in glycosylation, trafficking, or channel function, and did not affect cellular properties. We discovered that the Q5H variant is in fact the highly conserved ancestral allele of PANX1, with 89% of humans carrying at least one Q5H allele. Another mutated form Y150F, found in a melanoma patient tumour, prevented phosphorylation at Y150 as well as complex N-glycosylation, while increasing intracellular localization. SRC is the predicted kinase to phosphorylate the Y150 residue, and its phosphorylation is not likely to be constitutive, but rather dynamically regulated. The Y150 phosphorylation site is the first one reported to play a role in regulating post-translational modifications and trafficking of PANX1, with potential consequences on its large-pore channel structure and function in melanoma cells.

Pannexin 1 (PANX1) 是一种糖蛋白，可形成大孔通道，能够传递离子和代谢物（例如 ATP）以进行细胞通讯。 PANX1 与许多疾病有关，包括乳腺癌和黑色素瘤，其中 PANX1 的抑制或缺失会降低癌细胞的致瘤和转移特性。我们使用癌症患者肿瘤中报告的自然发生的变异来探究各个 PANX1 结构域中单个氨基酸变化的影响。我们发现先前报道的变体（Q5H）存在于癌细胞中，但在糖基化、运输或通道功能方面与野生型（Q5）没有不同，并且不影响细胞特性。我们发现 Q5H 变体实际上是 PANX1 高度保守的祖先等位基因，89% 的人类至少携带一个 Q5H 等位基因。在黑色素瘤患者肿瘤中发现的另一种突变形式 Y150F 可阻止 Y150 磷酸化以及复杂的 N-糖基化，同时增加细胞内定位。 SRC 是预计磷酸化 Y150 残基的激酶，其磷酸化不太可能是组成型的，而是动态调节的。 Y150 磷酸化位点是第一个被报道在调节 PANX1 翻译后修饰和运输中发挥作用的位点，对其大孔通道结构和黑色素瘤细胞中的功能具有潜在影响。