Identification of a novel nuclear speckle-type protein, SPOP

FEBS Lett. 1997 Nov 24;418(1-2):23-6. doi: 10.1016/s0014-5793(97)01340-9.


A novel antigen recognized by serum from a scleroderma patient was identified by expression cloning from the HeLa cell cDNA library. The cloned cDNA encoded a 374-amino acid protein with a relative molecular mass of 47,000 and a predicted amino acid sequence 62.7% identical to the hypothetical protein of Caenorhabditis elegans, T16H12.5. The deduced amino acid sequence had a typical POZ domain and an unidentified region conserved during evolution. No zinc finger or RNA recognition motifs were found in this clone. The 2 kbp mRNA encoding the novel clone SPOP (speckle-type POZ protein) was found to be expressed in all human tissues examined. HA-tagged SPOP, transfected and overexpressed in COS7 cells, exhibited a discrete speckled pattern in the nuclei and was co-localized with the splicing factor, snRNP B'/B. Deletion analysis revealed that both the POZ domain and the evolutionarily conserved region at the amino-terminus are required for the nuclear speckled accumulation of SPOP.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • COS Cells
  • Caenorhabditis elegans
  • Cloning, Molecular
  • Conserved Sequence
  • DNA, Complementary
  • Evolution, Molecular
  • Gene Library
  • HeLa Cells
  • Humans
  • Molecular Sequence Data
  • Nuclear Proteins / biosynthesis*
  • Nuclear Proteins / chemistry
  • RNA, Messenger / biosynthesis
  • Recombinant Proteins / biosynthesis
  • Recombinant Proteins / chemistry
  • Repressor Proteins
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Sequence Tagged Sites
  • Transcription, Genetic
  • Transfection


  • DNA, Complementary
  • Nuclear Proteins
  • RNA, Messenger
  • Recombinant Proteins
  • Repressor Proteins
  • SPOP protein, human

Associated data

  • GENBANK/AJ000644