Biosynthesis and processing of delta sleep-inducing peptide-like precursors in primary cultures of mouse anterior pituitary cells.
The biosynthesis and processing of material resembling delta sleep-inducing peptide (DSIP) have been studied in mouse anterior pituitary primary cell cultures. Cells were pulse/chase incubated with 3H-labelled amino acids (Gly, Arg or Ala) and cell extracts were immunoprecipitated with DSIP antiserum. Labelled DSIP-related proteins were resolved by SDS/PAGE. Multiple forms of DSIP-immunoprecipitable material were observed, including three precursors of molecular mass 50-60 kDa which were processed to two major groups of intermediates of 35-45 kDa and 9-16.5 kDa. These intermediates appear to be processed to a DSIP-related peptide (molecular mass less than 3 kDa), which co-ran on reversed-phase HPLC with an endogenous form of DSIP in mouse anterior pituitary, but not with rabbit DSIP. This less than 3-kDa peptide incorporated [3H]Gly, but not [3H]Arg or [3H]Ala. In addition, it incorporated [3H]glucosamine, indicating that it was a glycopeptide. Secretion studies showed release of the less than 3-kDa DSIP-like glycopeptide and the 9-16.5-kDa group of intermediates into the medium. The present study demonstrates the biosynthesis of a small DSIP-like glycopeptide in mouse anterior pituitary cells, which is not identical with, but has similarities to, rabbit DSIP.
Bjartell
A
A
Section on Cellular Neurobiology, National Institute of Child Health and Human Development, Bethesda, MD 20892.
Ekman
R
R
Loh
Y P
YP
D000818:Animals; D015153:Blotting, Western; D002478:Cells, Cultured; D002845:Chromatography / Q000379:methods; D002851:Chromatography, High Pressure Liquid; D003701:Delta Sleep-Inducing Peptide / Q000096:biosynthesis* / Q000276:immunology; D007106:Immune Sera / Q000032:analysis; D008297:Male; D051379:Mice; D010903:Pituitary Gland, Anterior / Q000378:metabolism*; D011498:Protein Precursors / Q000096:biosynthesis*; D011863:Radioimmunoassay
D007106:Immune Sera; D011498:Protein Precursors; D003701:Delta Sleep-Inducing Peptide