Implication of annexin 1 in phagocytosis: effects of n-terminal domain deletions and point mutations of the phosphorylation site Ser-27.
Directed mutagenesis, in the form of deletions and point mutations, was used to investigate the regulatory importance of the N-terminal domain of annexin 1. Wild-type and mutant forms were fused to green fluorescent protein (GFP) to track their localization and introduced in to J-774A.1 cells by transfection. The fusion of annexin 1 to GFP at the N- or C-terminal end did not alter the cellular distribution or co-localization with phagosomes. The effects of mutations were determined according to these characteristics. The prominent effect resulted from S27E mutation which mimics the phosphorylated state of Ser-27. Although still retaining the granular structures in the cytoplasm, S27E annexin 1 failed to associate with the phagosomal protein complex. This suggests an essential regulatory role of the phosphorylation of residue 27 in annexin 1 function.
Kusumawati
A
A
INSERM U-431, Université Montpellier II, Case no. 100, Place E. Bataillon, Montpellier, Cedex 5, 34095, France.
Liautard
J P
JP
Sri Widada
J
J
D000818:Animals; D017305:Annexin A1 / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D001665:Binding Sites / Q000235:genetics; D002460:Cell Line; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008856:Microscopy, Fluorescence; D010587:Phagocytosis / Q000502:physiology*; D010588:Phagosomes / Q000378:metabolism; D010766:Phosphorylation; D017354:Point Mutation; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D017384:Sequence Deletion; D012694:Serine / Q000235:genetics; D014162:Transfection
D017305:Annexin A1; D008164:Luminescent Proteins; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D012694:Serine