Biosynthesis of intestinal microvillar proteins. Translational evidence in vitro that aminopeptidase N is synthesized as a Mr-115000 polypeptide

Biosynthesis of intestinal microvillar proteins

The post-translational processing of pig small-intestinal aminopeptidase N (EC 3.4.11.2) was studied in organ-cultured mucosal explants. Exposure of the explants to swainsonine, an inhibitor of Golgi mannosidase II, resulted in the formation of a M,-160000 polypeptide, still sensitive to endo-ffi-N-acetylglucosaminidase H. Swainsonine caused only a moderate inhibition of transport of the enzyme...

Reassociation of microvillar core proteins: making a microvillar core in vitro

Intestinal epithelia have a brush border membrane of numerous microvilli each comprised of a cross-linked core bundle of 15-20 actin filaments attached to the surrounding membrane by lateral cross-bridges; the cross-bridges are tilted with respect to the core bundle. Isolated microvillar cores contain actin (42 kD) and three other major proteins: fimbrin (68 kD), villin (95 kD), and the 110K-ca...

Role of the Golgi complex and characteristics of post-Golgi transport in the biosynthesis of intestinal microvillar proteins.

Evidence that somatostatin is localized and synthesized in lymphoid organs.

Because several peptides originally found in the pituitary as within the central nervous system have been localized in lymphoid tissues and because somatostatin (somatotropin-release-inhibiting hormone, SRIH) can act on cells of the immune system, we searched for this peptide in lymphoid organs. We demonstrated that SRIH mRNA exists in lymphoid tissue, albeit in smaller levels than in the periv...

Proteins of the kidney microvillar membrane. Enzymic and molecular properties of aminopeptidase W.

Aminopeptidase W is a newly discovered enzyme of the renal and intestinal brush borders, having been first isolated as a 130 kDa glycoprotein recognized by a monoclonal antibody [Gee & Kenny (1985) Biochem. J. 230, 753-764]. It is particularly effective in the hydrolysis of dipeptides, Glu-Trp (Km 0.57 mM; kcat. 6770 min-1) being a favoured substrate. Dipeptides with tryptophan, phenylalanine o...