F-actin binds to the cytoplasmic surface of ponticulin, a 17-kD integral glycoprotein from Dictyostelium discoideum plasma membranes.
F-actin binds to the cytoplasmic surface of ponticulin, a 17-kD integral glycoprotein from Dictyostelium discoideum plasma membranes.
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DOI：
10.1083/jcb.105.4.1741
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发表时间：
1987-10
期刊：
影响因子：
--
通讯作者：
Luna EJ
中科院分区：
文献类型：
--
作者：
Wuestehube LJ;Luna EJ
F-肌动蛋白亲和层析和免疫学技术用于鉴定纯化的盘基网柄菌质膜中的肌动蛋白结合蛋白。在各种实验条件下，17-kD 整合糖蛋白 (gp17) 始终作为主要肌动蛋白结合蛋白从 F-肌动蛋白柱中洗脱。 gp17 的肌动蛋白结合活性与完整质膜的相同：它能抵抗 0.1 N NaOH、1 mM 二硫苏糖醇 (DTT) 的提取；对离子条件敏感；在较宽的 pH 范围内保持稳定；通过蛋白水解、加热变性或用DTT和N-乙基马来酰亚胺处理来消除。 gp17 可能负责质膜的大部分肌动蛋白结合活性，因为在沉降测定中，主要针对 gp17 的单价抗体片段 (Fab) 可抑制肌动蛋白膜结合 96%。相比之下，针对细胞表面决定簇的 Fab 仅抑制 0-10% 的结合。 gp17 的肌动蛋白结合位点似乎位于细胞膜的细胞质表面，因为即使在细胞表面广泛吸附后，针对该蛋白的 Fab 仍能继续抑制 96% 的肌动蛋白与膜的结合。 gp17在质膜中含量丰富，占总膜蛋白的0.4-1.0%。由于除了肌动蛋白结合位点的细胞质定位之外，还鉴定了 gp17 的细胞外决定簇，因此表明 gp17 具有跨膜方向。 gp17 由磺基-N-羟基-琥珀酰亚胺-生物素进行表面标记，这是一种无法穿透细胞膜的试剂。此外，gp17 是糖基化的，因为它与凝集素伴刀豆球蛋白 A 特异性结合。我们认为 gp17 是一种主要的肌动蛋白结合蛋白，对于将质膜连接到下面的微丝网络非常重要。因此，我们将这种蛋白质命名为“ponticulin”，源自拉丁文ponticulus，意思是小桥。
F-actin affinity chromatography and immunological techniques are used to identify actin-binding proteins in purified Dictyostelium discoideum plasma membranes. A 17-kD integral glycoprotein (gp17) consistently elutes from F-actin columns as the major actin-binding protein under a variety of experimental conditions. The actin-binding activity of gp17 is identical to that of intact plasma membranes: it resists extraction with 0.1 N NaOH, 1 mM dithiothreitol (DTT); it is sensitive to ionic conditions; it is stable over a wide range of pH; and it is eliminated by proteolysis, denaturation with heat, or treatment with DTT and N- ethylmaleimide. gp17 may be responsible for much of the actin-binding activity of plasma membranes since monovalent antibody fragments (Fab) directed primarily against gp17 inhibit actin-membrane binding by 96% in sedimentation assays. In contrast, Fab directed against cell surface determinants inhibit binding by only 0-10%. The actin-binding site of gp17 appears to be located on the cytoplasmic surface of the membrane since Fab against this protein continue to inhibit 96% of actin- membrane binding even after extensive adsorption against cell surfaces. gp17 is abundant in the plasma membrane, constituting 0.4-1.0% of the total membrane protein. A transmembrane orientation of gp17 is suggested since, in addition to the cytoplasmic localization of the actin-binding site, extracellular determinants of gp17 are identified. gp17 is surface-labeled by sulfo-N-hydroxy-succinimido-biotin, a reagent that cannot penetrate the cell membrane. Also, gp17 is glycosylated since it is specifically bound by the lectin, concanavalin A. We propose that gp17 is a major actin-binding protein that is important for connecting the plasma membrane to the underlying microfilament network. Therefore, we have named this protein "ponticulin" from the Latin word, ponticulus, which means small bridge.
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影响因子：
7.8
作者：
Cocucci, S M;Sussman, M
通讯作者：
Sussman, M
DOI：
10.1111/j.1749-6632.1974.tb53040.x
发表时间：
1974-01-01
影响因子：
5.2
作者：
GOLDSTEIN, IJ;REICHERT, CM;MISAKI, A
通讯作者：
MISAKI, A
影响因子：
7.8
作者：
BROWN, SS;PETZOLD, AS
通讯作者：
PETZOLD, AS
DOI：
10.1073/pnas.72.5.1758
发表时间：
1975-01-01
影响因子：
11.1
作者：
CLARKE, M;SCHATTEN, G;SPUDICH, JA
通讯作者：
SPUDICH, JA
DOI：
10.1073/pnas.74.11.5031
发表时间：
1977-01-01
影响因子：
11.1
作者：
BOURGUIGNON, LYW;SINGER, SJ
通讯作者：
SINGER, SJ