title: Isolation of a novel member of small G protein superfamily and its expression in colon cancer.
abstract: OBJECTIVE
  APMCF1 is a novel human gene whose transcripts are up-regulated in apoptotic MCF-7 cells. In order to learn more about this gene's function in other tumors, we cloned its full length cDNA and prepared its polyclonal antibody to investigate its expression in colon cancers with immunohistochemistry.
  
  
  METHODS
  With the method of 5' rapid amplification of cDNA end (RACE) and EST assembled in GenBank, we extended the length of APMCF1 at 5' end. Then the sequence encoding the APMCF1 protein was amplified by RT-PCR from the total RNA of apoptotic MCF-7 cells and cloned into the prokaryotic expression vector pGEX-KG to construct recombinant expression vector pGEX-APMCF1. The GST-APMCF1 fusion protein was expressed in E. coli and used to immunize rabbits to get the rabbit anti-APMCF1 serum. The specificity of polyclonal anti-APMCF1 antibody was determined by Western blot. Then we investigated the expression of Apmcf1 in colon cancers and normal colonic mucosa with immunohistochemistry.
  
  
  RESULTS
  A cDNA fragment with a length of 1 745 bp was obtained. APMCF1 was mapped to chromosome 3q22.2 and spanned at least 14.8 kb of genomic DNA with seven exons and six introns contained. Bioinformatic analysis showed the protein encoded by APMCF1 contained a small GTP-binding protein (G proteins) domain and was homologous to mouse signal recognition particle receptor beta(SRbeta). A coding region covering 816 bp was cloned and polyclonal anti-APMCF1 antibody was prepared successfully. The immunohistochemistry study showed that APMCF1 had a strong expression in colon cancer.
  
  
  CONCLUSIONS
  APMCF1 may be the gene coding human signal recognition particle receptor beta and belongs to the small-G protein superfamily. Its strong expression pattern in colon cancer suggests it may play a role in colon cancer development.
authors.affiliation: Department of Patholology, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, Shaanxi Province, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Yan
authors.forename: Wen-Liang
authors.initials: WL
authors.lastname: Wang
authors.forename: Feng
authors.initials: F
authors.lastname: Zhu
authors.forename: Sheng-Quan
authors.initials: SQ
authors.lastname: Chen
authors.forename: Qing-Long
authors.initials: QL
authors.lastname: Li
authors.forename: Li
authors.initials: L
authors.lastname: Wang
mesh_terms: D000595:Amino Acid Sequence / Q000235:genetics; D001483:Base Sequence / Q000235:genetics; D002460:Cell Line; D003110:Colonic Neoplasms / Q000378:metabolism*; D018076:DNA, Complementary / Q000235:genetics; D019204:GTP-Binding Proteins; D006801:Humans; D007150:Immunohistochemistry; D008969:Molecular Sequence Data; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*
chemical_list: D018076:DNA, Complementary; D011518:Proto-Oncogene Proteins; C449560:SRPRB protein, human; D019204:GTP-Binding Proteins