Primary structure of the human splicing factor ASF reveals similarities with Drosophila regulators

Cell. 1991 Jul 26;66(2):373-82. doi: 10.1016/0092-8674(91)90626-a.


We described previously the purification of a human protein, called alternative splicing factor (ASF), that can switch utilization of alternative 5' splice sites in an SV40 early pre-mRNA. We now report the isolation of a cDNA, designated ASF-1, that encodes this protein. ASF-1 consists of 248 amino acid residues, including an 80 residue RNA-binding domain at its N-terminus and a 50 residue C-terminal region that is 80% serine plus arginine. ASF-1 produced in E. coli can activate splicing in vitro and switch 5' splice-site utilization, establishing that the recombinant protein is sufficient to supply these activities. Analysis of additional cDNAs revealed that ASF pre-mRNA can itself be alternatively spliced, surprisingly, by utilization of a shared 5' splice site and two closely spaced 3' splice sites. Use of the upstream site results in a second mRNA (ASF-2) in which translation of the downstream exon occurs extensively in an alternative reading frame distinct from ASF-1.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Cell Line
  • Cloning, Molecular
  • DNA / genetics
  • DNA / isolation & purification
  • Drosophila / genetics*
  • Escherichia coli / genetics
  • Gene Expression
  • Humans
  • Molecular Sequence Data
  • Nuclear Proteins / genetics*
  • Nuclear Proteins / metabolism
  • Oligonucleotide Probes
  • Protein Conformation
  • RNA Precursors / genetics
  • RNA Splicing*
  • RNA-Binding Proteins
  • Recombinant Proteins / metabolism
  • Sequence Homology, Nucleic Acid
  • Serine-Arginine Splicing Factors


  • Nuclear Proteins
  • Oligonucleotide Probes
  • RNA Precursors
  • RNA-Binding Proteins
  • Recombinant Proteins
  • Serine-Arginine Splicing Factors
  • DNA

Associated data

  • GENBANK/M60962
  • GENBANK/M64383
  • GENBANK/M64384
  • GENBANK/M72709
  • GENBANK/S44115
  • GENBANK/S44157
  • GENBANK/S44159
  • GENBANK/S44161
  • GENBANK/S56137
  • GENBANK/S56139