A human gene encoding a putative basic helix-loop-helix phosphoprotein whose mRNA increases rapidly in cycloheximide-treated blood mononuclear cells.
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.
Siderovski
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DP
Department of Biochemistry, Queen's University, Kingston, Ontario, Canada.
Heximer
S P
SP
Forsdyke
D R
DR
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002453:Cell Cycle / Q000235:genetics; D003513:Cycloheximide / Q000494:pharmacology*; D004247:DNA; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics*; D005809:Genes, Regulator; D018257:Helix-Loop-Helix Motifs; D006801:Humans; D007256:Information Systems; D008969:Molecular Sequence Data; D009000:Monocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D016366:Open Reading Frames; D010750:Phosphoproteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D020710:RGS Proteins; D012333:RNA, Messenger / Q000378:metabolism
D004268:DNA-Binding Proteins; D010750:Phosphoproteins; D020710:RGS Proteins; C087182:RGS2 protein, human; D012333:RNA, Messenger; D004247:DNA; D003513:Cycloheximide