A COMMON PRECURSOR TO NEUROTENSIN AND LANT6 AND ITS DIFFERENTIAL PROCESSING IN CHICKEN TISSUES

Antisera towards neurotensin (NT) and the structurally related peptide , LANT6, were used to characterize immunoreactive peptides and protein s in extracts of chicken tissues. A 17 kDa protein was identified by W estern blotting as a potential precursor to NT and LANT6. However, the posttranslational processing of this common precursor appeared to be tissue specific, giving rise to disproportionate amounts of NT and LAN T6, along with varying expression of a large molecular LANT6 (M(r), 15 kDa). The intestinal cells containing immunoreactive NT, LANT6, and l arge molecular LANT6 behaved similarly during fractionation by size an d density. These activities also banded together in particles resembli ng vesicles during centrifugation of isotonic homogenates of tissue. T hese results suggest that chicken NT and LANT6 are biosynthesized as p arts of the same precursor, the processing of which can give rise to a variety of products stored within secretory vesicles.