Identification of a Golgi GPI-N-acetylgalactosamine transferase with tandem transmembrane regions in the catalytic domain.
Identification of a Golgi GPI-N-acetylgalactosamine transferase with tandem transmembrane regions in the catalytic domain.
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在催化结构域中用串联跨膜区域的高尔基GPI GPI-N-乙酰乳糖苷转移酶的鉴定。
DOI：
10.1038/s41467-017-02799-0
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发表时间：
2018-01-26
影响因子：
16.6
通讯作者：
Kinoshita T
中科院分区：
文献类型：
--
作者：
Hirata T;Mishra SK;Nakamura S;Saito K;Motooka D;Takada Y;Kanzawa N;Murakami Y;Maeda Y;Fujita M;Yamaguchi Y;Kinoshita T
许多真核生物蛋白质通过糖脂糖基磷脂酰肌醇（GPI）锚定在细胞表面。哺乳动物GPIs具有保守的核心，但表现出不同的N-乙酰半乳糖胺（GalNAc）修饰，这些修饰是通过尚未解决的过程添加的。在这里，我们确定高尔基体居民GPI-GalNAc转移酶PGAP 4和显示通过质谱分析，PGAP 4敲除细胞失去GPI-GalNAc结构。此外，我们证明PGAP 4与已知的高尔基体糖基转移酶相反，不是单程膜蛋白，而是包含三个跨膜结构域，包括插入其糖基转移酶-A折叠的串联跨膜结构域，如比较建模所示。突变分析揭示了一个催化位点，一个DXD样基序UDP-GalNAc供体结合，和几个残基可能参与受体结合。我们认为，PGAP 4的质膜区域容纳各种GPI锚定蛋白，呈现其受体残基朝向催化中心。总之，我们提出了PGAP 4的结构的见解，并阐明了GPI-GalNAc生物合成的初始步骤。哺乳动物GPI膜锚被GalNAc修饰以赋予结构多样性，但生物合成途径知之甚少。在这里，作者确定和表征高尔基体驻留GPI-GalNAc转移酶PGAP 4，提供了GPI-GalNAc生物合成的初始步骤的见解。
Many eukaryotic proteins are anchored to the cell surface via the glycolipid glycosylphosphatidylinositol (GPI). Mammalian GPIs have a conserved core but exhibit diverse N-acetylgalactosamine (GalNAc) modifications, which are added via a yet unresolved process. Here we identify the Golgi-resident GPI-GalNAc transferase PGAP4 and show by mass spectrometry that PGAP4 knockout cells lose GPI-GalNAc structures. Furthermore, we demonstrate that PGAP4, in contrast to known Golgi glycosyltransferases, is not a single-pass membrane protein but contains three transmembrane domains, including a tandem transmembrane domain insertion into its glycosyltransferase-A fold as indicated by comparative modeling. Mutational analysis reveals a catalytic site, a DXD-like motif for UDP-GalNAc donor binding, and several residues potentially involved in acceptor binding. We suggest that a juxtamembrane region of PGAP4 accommodates various GPI-anchored proteins, presenting their acceptor residue toward the catalytic center. In summary, we present insights into the structure of PGAP4 and elucidate the initial step of GPI-GalNAc biosynthesis. Mammalian GPI membrane anchors are modified by GalNAc to confer structural diversity but the biosynthetic pathway is poorly understood. Here, the authors identify and characterize the Golgi-resident GPI-GalNAc transferase PGAP4, providing insights into the initial step of GPI-GalNAc biosynthesis.
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影响因子：
2.9
作者：
JONES, DT;TAYLOR, WR;THORTON, JM
通讯作者：
THORTON, JM
DOI：
10.1007/s00018-015-2066-0
发表时间：
2016-01
期刊：
Cellular and molecular life sciences : CMLS
影响因子：
--
作者：
Kellokumpu S;Hassinen A;Glumoff T
通讯作者：
Glumoff T
影响因子：
4.8
作者：
BREWIS, IA;FERGUSON, MAJ;HOOPER, NM
通讯作者：
HOOPER, NM
影响因子：
14.9
作者：
Käll L;Krogh A;Sonnhammer EL
通讯作者：
Sonnhammer EL
影响因子：
64.5
作者：
Fujita, Morihisa;Maeda, Yusuke;Kinoshita, Taroh
通讯作者：
Kinoshita, Taroh