Preparation and characterizations of polyclonal antibodies against STAR protein QKI7b

Appl Biochem Biotechnol. 2013 Apr;169(8):2273-80. doi: 10.1007/s12010-012-0081-2. Epub 2013 Feb 26.

Abstract

Quaking (QKI) proteins are important regulators of RNA metabolism and cellular signal transduction. Recent studies have shown that isoforms of QKI proteins, which include QKI5/6/7/7b in human cells, play important roles in the development of neurological diseases and human cancers. In comparison with QKI5/6/7, however, there are little data on QKI7b due to lack of specific antibodies. Here, we reported the preparation and initial characterizations of polyclonal antibodies against human QKI7b. Utilizing a chemically synthesized C-terminal peptide fragment of human QKI7b, we raised two preparations of rabbit antiserum. We found that these antibodies were able to recognize human QKI7b, but not QKI5/6/7. Our immunofluorescence staining showed that in LO2 hepatocytes, QKI7b localizes predominantly in the perinuclear cytoplasm and less abundantly in the nucleus. In clinical samples, we showed that like QKI5/6/7 proteins, QKI7b protein was also significantly downregulated in most human colorectal cancer tissues. These antibodies, therefore, might be useful in future functional studies of QKI7b.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies / immunology
  • Antibodies / metabolism*
  • Blotting, Western
  • Cell Line
  • Colorectal Neoplasms / metabolism
  • Enzyme-Linked Immunosorbent Assay
  • Fluorescent Antibody Technique
  • Hemocyanins / chemistry
  • Humans
  • In Vitro Techniques
  • RNA-Binding Proteins / immunology
  • RNA-Binding Proteins / metabolism*
  • Rabbits
  • Reverse Transcriptase Polymerase Chain Reaction

Substances

  • Antibodies
  • QKI protein, human
  • RNA-Binding Proteins
  • Hemocyanins