Starvation Induces Extracellular Accumulation of Polyphosphate in Dictyostelium discoideum to Inhibit Macropinocytosis, Phagocytosis, and Exocytosis.
Starvation Induces Extracellular Accumulation of Polyphosphate in Dictyostelium discoideum to Inhibit Macropinocytosis, Phagocytosis, and Exocytosis.
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DOI：
10.3390/ijms24065923
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发表时间：
2023-03-21
影响因子：
5.6
通讯作者：
Gomer, Richard H.
中科院分区：
文献类型：
--
作者：
Rijal, Ramesh;Ismail, Issam;Jing, Shiyu;Gomer, Richard H.
盘基网柄藻（Dictyostelium discoideum）是一种生活在土壤中的单细胞真核生物，能积累胞外多磷酸盐（polyP）。在高细胞密度下，当细胞即将过度生长其食物供应并饥饿时，相应的高细胞外聚P浓度允许细胞抢先预测饥饿，抑制增殖，并使其自身准备好开始发育。在这份报告中，我们发现饥饿的D. discoideum细胞积累细胞表面和细胞外polyP。饥饿减少巨胞饮作用、胞吐作用和吞噬作用，并且我们发现这些作用需要G蛋白偶联的聚P受体（GrlD）和两种酶，聚磷酸激酶1（Ppk 1），其是合成细胞内聚P、细胞表面聚P和一些细胞外聚P所需的，以及肌醇六磷酸激酶（I6 kA），其是细胞表面聚P和聚P与细胞结合所需的，和一些细胞外的polyP。PolyP降低膜流动性，我们发现饥饿降低膜流动性;这种作用需要GrlD和Ppk 1，但不需要I6 kA。总之，这些数据表明，在饥饿的细胞，细胞外聚P降低膜流动性，可能作为一种保护措施。在饥饿的细胞中，感觉polyP似乎减少了摄入的能量消耗，减少了胞吐作用，并且既减少了能量消耗又保留了营养。
Dictyostelium discoideum is a soil-dwelling unicellular eukaryote that accumulates extracellular polyphosphate (polyP). At high cell densities, when the cells are about to overgrow their food supply and starve, the corresponding high extracellular concentrations of polyP allow the cells to preemptively anticipate starvation, inhibit proliferation, and prime themselves to begin development. In this report, we show that starved D. discoideum cells accumulate cell surface and extracellular polyP. Starvation reduces macropinocytosis, exocytosis, and phagocytosis, and we find that these effects require the G protein-coupled polyP receptor (GrlD) and two enzymes, Polyphosphate kinase 1 (Ppk1), which is required for synthesizing intracellular polyP, cell surface polyP, and some of the extracellular polyP, and Inositol hexakisphosphate kinase (I6kA), which is required for cell surface polyP and polyP binding to cells, and some of the extracellular polyP. PolyP reduces membrane fluidity, and we find that starvation reduces membrane fluidity; this effect requires GrlD and Ppk1, but not I6kA. Together, these data suggest that in starved cells, extracellular polyP decreases membrane fluidity, possibly as a protective measure. In the starved cells, sensing polyP appears to decrease energy expenditure from ingestion, and decrease exocytosis, and to both decrease energy expenditures and retain nutrients.
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DOI：
10.1073/pnas.74.5.2157
发表时间：
1977-01-01
影响因子：
11.1
作者：
FRANKE, J;KESSIN, R
通讯作者：
KESSIN, R
影响因子：
--
作者：
Phillips, Jonathan E.;Gomer, Richard H.
通讯作者：
Gomer, Richard H.
影响因子：
7.7
作者：
Bloomfield G;Traynor D;Sander SP;Veltman DM;Pachebat JA;Kay RR
通讯作者：
Kay RR
影响因子：
2.7
作者：
Aschar-Sobbi, Roozbeh;Abramov, Andrey Y.;Pavlov, Evgeny
通讯作者：
Pavlov, Evgeny
影响因子：
2
作者：
Laasmaa M;Vendelin M;Peterson P
通讯作者：
Peterson P