CUG initiation codon used for the synthesis of a cell surface antigen coded by the murine leukemia virus

MLV glycosylated-Gag is an infectivity factor that rescues Nef-deficient HIV-1

“…Most gammaretroviruses encode a glycosylated transmembrane Gag molecule (glycogag or gPr80) translated from a CUG initiation codon upstream and in-frame with gag (35)(36)(37)(38)(39). To test the possibility that glycogag is capable of rescuing the infectivity defect of HIV-1 nef-, a mutant genome unable to encode gPr80 (MLV gg-) was obtained by changing the "CUG" start codon to "CA"; this mutation introduces both a nucleotide change and a frameshift.…”

“…Most gammaretroviruses encode an accessory protein (gPr80 or glycogag) from unspliced RNA via an alternative CUG initiation codon upstream and in-frame with the standard Gag polyprotein (35)(36)(37)(38)(39). As a result, a leader sequence [88 amino acids in MLV provirus genome (MoMLV)] is added to the N terminus of conventional Gag.…”

Mouse retroviruses and chronic fatigue syndrome: Does X (or P) mark the spot?

“…Over 30 y ago, extracellular glycosylated forms of the MLV Gag proteins were identified (8) and found to be translated from an alternative CTG initiation codon in-frame with the conventional gag ATG to append a type II leader sequence to the Gag precursor (9) (Fig. 1B).…”

Murine leukemia virus glycosylated Gag (gPr80 gag ) facilitates interferon-sensitive virus release through lipid rafts

“…One unique feature of MuLVs and many other gammaretroviruses is that they encode an additional form of Gag polyprotein, gPr80 gag , and a corresponding Gag-Pol polyprotein. gPr80 gag is translated from unspliced viral mRNA via an upstream CUG initiation codon in the same reading frame as the Pr65 gag precursor for viral core proteins (1)(2)(3). gPr80 gag contains 88 additional amino-terminal amino acids, including a signal peptide that leads to transport of the protein into the rough endoplasmic reticulum, where it is glycosylated and exported to the cell surface (4) and cleaved into two proteins of ≈55 and 40 kDa (1,5); the aminoterminal protein is reinserted through the plasma membrane, with the N-terminal unique sequences exposed to the cytoplasm (4).…”