A human gene encoding a putative basic helix-loop-helix phosphoprotein whose mRNA increases rapidly in cycloheximide-treated blood mononuclear cells

DNA Cell Biol. 1994 Feb;13(2):125-47. doi: 10.1089/dna.1994.13.125.


G0S8 is a member of a set of putative G0/G1 switch regulatory genes (G0S genes) selected by screening cDNA libraries prepared from blood mononuclear cells cultured for 2 hr with lectin and cycloheximide. Comparison of a full-length cDNA sequence with the corresponding genomic sequence reveals an open reading frame of 211 amino acids, distributed across 5 exons. The 24-kD protein has a basic domain preceding a potential helix-loop-helix domain which contains a QTK motif found about 60 amino acids from the carboxyl terminus in the loop region of several helix-loop-helix proteins. There are potential phosphorylation sites for protein kinase C, creatine kinase II, and protein tyrosine kinases and regions of sequence similarity to helix-loop-helix proteins, tyrosine phosphatases, and RNA and DNA polymerases. The genomic sequence contains a CpG island, suggesting expression in the germ line. Potential binding sites for transcription factors are present in the 5' flank and introns; these include Zif268/NGFI-A/EGR1/G0S30, NGFI-B, Ap1, and factors that react with retroviral long terminal repeats (LTRs). There are several potential interferon response elements and a serum response element in the 3' flank overlapping a region of similarity to a cytomegalovirus immediate-early gene enhancer. Many of these motifs are found in immediate-early G0/G1 switch genes; however, we were unable to demonstrate an increase in G0S8 mRNA in response to lectin alone. Sequence similarities are noted between G0S8 and a variety of genes involved in the immune system, in the regulation of retroviruses, and in the cell cycle.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Binding Sites
  • Cell Cycle / genetics
  • Cycloheximide / pharmacology*
  • DNA
  • DNA-Binding Proteins / chemistry
  • DNA-Binding Proteins / genetics*
  • Genes, Regulator
  • Helix-Loop-Helix Motifs*
  • Humans
  • Information Systems
  • Molecular Sequence Data
  • Monocytes / cytology
  • Monocytes / drug effects
  • Monocytes / metabolism
  • Open Reading Frames
  • Phosphoproteins / biosynthesis
  • Phosphoproteins / chemistry
  • Phosphoproteins / genetics*
  • RGS Proteins*
  • RNA, Messenger / metabolism


  • DNA-Binding Proteins
  • Phosphoproteins
  • RGS Proteins
  • RGS2 protein, human
  • RNA, Messenger
  • DNA
  • Cycloheximide

Associated data

  • GENBANK/L13391
  • GENBANK/L13463