THE RING-INFECTED ERYTHROCYTE SURFACE-ANTIGEN PROTEIN OF PLASMODIUM-FALCIPARUM IS PHOSPHORYLATED UPON ASSOCIATION WITH THE HOST-CELL MEMBRANE
THE RING-INFECTED ERYTHROCYTE SURFACE-ANTIGEN PROTEIN OF PLASMODIUM-FALCIPARUM IS PHOSPHORYLATED UPON ASSOCIATION WITH THE HOST-CELL MEMBRANE
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DOI：
10.1016/0166-6851(90)90206-2
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发表时间：
1990-01-01
影响因子：
1.5
通讯作者：
ANDERS, RF
中科院分区：
文献类型：
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作者：
FOLEY, M;MURRAY, LJ;ANDERS, RF
环状感染的红细胞表面抗原（RESA）是一种155-kDa的疟疾多肽，其从裂殖子释放并在侵入时与红细胞膜结合。由恶性疟原虫感染的红细胞制备的由内而外的囊泡（IOV）含有RESA，推测其与膜骨架结合，因为其在Triton X-100中基本不溶。当这些IOV与[γ- 32 P]ATP，一种155-kDa多肽，在来自感染的而不是来自未感染的红细胞的IOV中被标记。使用特异性兔抗血清的免疫沉淀证实RESA确实是一种磷蛋白。磷酸氨基酸分析显示磷酸丝氨酸和少量磷酸苏氨酸，但没有磷酸酪氨酸。在培养物中用无机[32 P]磷酸盐标记完整的寄生红细胞数小时，导致Triton不溶性提取物中的RESA被磷酸化。同步寄生虫的标记表明，RESA磷酸化，只有当它成为与红细胞膜，虽然RESA是丰富的成熟寄生虫，它是不是磷酸化。RESA，在恶性疟原虫生长期间释放到培养物上清液中，与从正常未感染红细胞制备的IOV结合，随后用（γ-）标记[32 P]ATP导致RESA磷酸化。有证据表明，RESA是由红细胞膜激酶磷酸化，而可能不是由寄生虫编码的酶。
The ring-infected erythrocyte surface antigen (RESA) is a 155-kDa a malarial polypeptide which is released from merozoites and becomes associated with the erythrocyte membrane at the time of invasion. Inside-out vesicles (IOVs) prepared from Plasmodium falciparum-infected erythrocytes contain RESA, presumably bound to the membrane skeleton, as it is largely insoluble in Triton X-100. When these IOVs were incubated with [.gamma.-32P]ATP, a 155-kDa polypeptide was labeled in IOVs from infected, but not from uninfected erythrocytes. Immunoprecipitation using specific rabbit antisera confirmed that RESA is indeed a phosphoprotein. Phosphoamino acid analysis revealed phosphoserine and a small amount of phosphotothreonine, but no phosphotyrosine. Labeling of intact parasitized erythrocytes with inorganic [32P]phosphate for several hours in culture resulted in RESA in Triton-insoluble extracts being phosphorylated. Labeling of synchronized parasites showed that RESA was phosphorylated only when it became associated with the erythrocyte membrane, and although RESA was abundant in mature parasites, it was not phosphorylated. RESA, released into the culture supernatants during the growth of P. falciparum bound to IOVs prepared from normal uninfected erythrocytes, and subsequent labeling with (.gamma.-32P]ATP resulted in the phosphorylation of RESA. The evidence suggests that RESA is phosphorylated by an erythrocyte membrane kinase and probably not by a parasite-encoded enzyme.