The AVIT protein family

Abstract

Homologues of a protein originally isolated from snake venom and frog skin secretions are present in many vertebrate species. They contain 80-90 amino acids, 10 of which are cysteines with identical spacing. Various names have been given to these proteins, such as mamba intestinal protein 1 (MIT1), Bv8 (Bombina variegata molecular mass ~8 kDa), prokineticins and endocrine-gland vascular endothelial growth factor (EG-VEGF). Their amino-terminal sequences are identical, and so we propose that the sequence of their first four residues, AVIT, is used as a name for this family. From a comparison of the sequences, two types of AVIT proteins can be discerned. These proteins seem to be distributed widely in mammalian tissues and are known to bind to G-protein-coupled receptors. Members of this family have been shown to stimulate contraction of the guinea pig ileum, to cause hyperalgesia after injection into rats and to be active as specific growth factors. Moreover, the messenger RNA level of one of these AVIT proteins changes rhythmically in the region of the brain known as the suprachiasmatic nucleus. This shows that members of this new family of small proteins are involved in diverse biological processes.

Function and biological roles of the Dickkopf family of Wnt modulators

“…Colipases are necessary for lipid hydrolysis by pancreatic lipases and interact with lipid micelles (van Tilbeurgh et al, 1999). The colipase fold is found in a wide range of proteins other than colipases, including, for example, toxins from funnel web spider (Szeto et al, 2000), black mamba (Boisbouvier et al, 1998) and frog skin (Bv8) as well as in protease inhibitors (Kaser et al, 2003). The structure of the colipase fold is solved and it consists of short b-strands connected by loops and stabilized by disulfide bonds, resulting in finger-like structures, that may serve as interactive surfaces (van Tilbeurgh et al, 1999).…”

Mitogenic functions of endocrine gland-derived vascular endothelial growth factor and Bombina variegata 8 on steroidogenic adrenocortical cells

“…Recently, a novel family of secreted proteins comprising about 80 amino acids and possessing the N-terminal amino acid sequence AVITGAC has been characterized and named the AVIT protein family (Kaser et al 2003). Among these members, endocrine gland-derived-VEGF (EG-VEGF) and Bombina variegata 8 (Bv8) represent a novel class of angiogenic factors with expression profiles restricted to endocrine glands and a few other tissues, and with selective mitogenic, motogenic, and prosurvival activities for endocrine glandderived endothelial cells (LeCouter & Ferrara 2003.…”

Bv8 and endocrine gland-derived vascular endothelial growth factor stimulate hematopoiesis and hematopoietic cell mobilization

“…prokineticins ͉ angiogenesis ͉ G protein-coupled receptor B v8 (1,2) and endocrine gland-derived VEGF (EG-VEGF) (3), secreted proteins also referred to as prokineticin-2 and -1, respectively (4,5), are structurally related to a larger class of peptides that are defined by a five disulphide-bridged motif called a colipase fold (6)(7)(8). We previously demonstrated that these ligands promote proliferation of endothelial cells derived from the adrenal cortex and stimulate angiogenic responses in the ovary (3) and testis (2).…”