title: [Nucleolar localization of human acetyltransferase-like protein and its expression in tumors].
abstract: OBJECTIVE
  To confirm the nucleolar localization of telomerase-regulation associated protein-human N-acetyltransferase-like protein (hALP) and its associated functions.
  
  
  METHODS
  Immunofluoresent staining and immunoelectron microscopy were used to detect the distribution of hALP in HeLa and Saos2 cells, and the co-localization of hALP and rDNA was analyzed by fluorescence in situ hybridization and immunofluoresence. RNAi was performed to further verify the nucleolar localization of hALP. A series of eukaryotic expression plasmids carrying various portions of hALP sequence were constructed and transiently transfected to HeLa and Saos2 cells. The expression of hALP in tumor tissues was stained by immunohistochemistry.
  
  
  RESULTS
  hALP distributed predominantly in the nucleoli of HeLa and Saos2 cells, and colocalized with rDNA. Granular component was the precise distribution of hALP in the nucleolus under electron microscope. Nucleolar signals for hALP reduced significantly in cells transfected with hALP siRNA. The carboxy terminus of hALP including residues 549-834 was necessary for its nucleolar localization. hALP could be detected in the nucleoli of many kinds of tumor cells, including leiomyosarcoma, primitive neuroectodermal tumor, neuroblastoma, melanoma, prostatic cancer, and clear cell renal carcinoma.
  
  
  CONCLUSIONS
  hALP is a nucleolar protein, and the nucleolar localization is mediated by its carboxy terminal domain, and hALP could be detected in the nucleoli of many tumor tissues, which is worthy of further investigation.
authors.affiliation: Department of Pathology, Peking University School of Basic Medical Sciences, Beijing, China.
authors.forename: Li-zhao
authors.initials: LZ
authors.lastname: Guan
authors.forename: Qi
authors.initials: Q
authors.lastname: Shen
authors.forename: Ying
authors.initials: Y
authors.lastname: Sun
authors.forename: Jiao-chen
authors.initials: JC
authors.lastname: Wang
authors.forename: Yi-lei
authors.initials: YL
authors.lastname: Gong
authors.forename: Lin
authors.initials: L
authors.lastname: Hou
authors.forename: Bo
authors.initials: B
authors.lastname: Zhang
mesh_terms: D001215:Asparaginase / Q000235:genetics / Q000378:metabolism*; D001324:Autoantigens / Q000235:genetics / Q000378:metabolism*; D002466:Cell Nucleolus / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic; D006367:HeLa Cells; D006801:Humans; D009369:Neoplasms / Q000378:metabolism*
chemical_list: D001324:Autoantigens; C466840:ASRGL1 protein, human; D001215:Asparaginase