Dataset Information

The Apaf-1-binding protein Aven is cleaved by Cathepsin D to unleash its anti-apoptotic potential.

ABSTRACT: The anti-apoptotic molecule Aven was originally identified in a yeast two-hybrid screen for Bcl-x(L)-interacting proteins and has also been found to bind Apaf-1, thereby interfering with Apaf-1 self-association during apoptosome assembly. Aven is expressed in a wide variety of adult tissues and cell lines, and there is increasing evidence that its overexpression correlates with tumorigenesis, particularly in acute leukemias. The mechanism by which the anti-apoptotic activity of Aven is regulated remains poorly understood. Here we shed light on this issue by demonstrating that proteolytic removal of an inhibitory N-terminal Aven domain is necessary to activate the anti-apoptotic potential of the molecule. Furthermore, we identify Cathepsin D (CathD) as the protease responsible for Aven cleavage. On the basis of our results, we propose a model of Aven activation by which its N-terminal inhibitory domain is removed by CathD-mediated proteolysis, thereby unleashing its cytoprotective function.

SUBMITTER: Melzer IM

PROVIDER: S-EPMC3422468 | biostudies-literature | 2012 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

The Apaf-1-binding protein Aven is cleaved by Cathepsin D to unleash its anti-apoptotic potential.

Melzer I M IM Fernández S B M SB Bösser S S Lohrig K K Lewandrowski U U Wolters D D Kehrloesser S S Brezniceanu M-L ML Theos A C AC Irusta P M PM Impens F F Gevaert K K Zörnig M M

Cell death and differentiation 20120302 9

The anti-apoptotic molecule Aven was originally identified in a yeast two-hybrid screen for Bcl-x(L)-interacting proteins and has also been found to bind Apaf-1, thereby interfering with Apaf-1 self-association during apoptosome assembly. Aven is expressed in a wide variety of adult tissues and cell lines, and there is increasing evidence that its overexpression correlates with tumorigenesis, particularly in acute leukemias. The mechanism by which the anti-apoptotic activity of Aven is regulated ...[more]

PMID: 22388353

Similar Datasets

Project description:Apoptosis plays a pivotal role in embryogenesis and postnatal cell homeostasis, involving DNA or subcellular fragmentation, and shedding of small membranous microvesicles termed apoptotic bodies (AB). Following DNA damage, hypoxia, or vascular injury, the chemokine CXCL12 has been implicated in the recruitment of progenitor cells for tissue regeneration through its receptor CXCR4 and in mechanisms counteracting apoptosis. Whether AB deliver alarm signals for regenerative responses to neighbouring cells beyond recruitment or eat-me signals for phagocytes and relevance to diseases with abundant apoptosis, eg atherosclerosis, remains unknown. Here we show that endothelial cell-derived AB are generated during diet-induced atherosclerosis and can be transferred to recipient endothelial or smooth muscle cells to induce functional expression of CXCL12. This is mediated through miRNA-126 enriched in AB, which acts by silencing RGS16 translation and unlocking CXCR4 to unleash an auto-regulatory feedback loop inducing CXCL12. Injection of AB promoted mobilization and incorporation of progenitor cells, reducing diet-induced atherosclerosis in apolipoprotein E-deficient mice, and local transfer of microRNA-126 inhibited collar-induced arterial plaque formation. This was associated with increased smooth muscle content but decreased macrophage and apoptotic cell content, all features of plaque stability. Our data identify a new mechanism, by which AB confer microRNA-126 as a paracrine alarm messenger to enhance CXCR4 signals and CXCL12 expression, thereby limiting or repairing vascular damage. This adds to the important functions of microRNAs in health and disease and may extend to progenitor cell recruitment during other forms of tissue repair or homeostasis. AB were isolated from supernatants of apoptotic, serum-starved human umbilical vein endothelial cells (HUVECs) by sequential centrifugation steps. Total RNA was isolated from AB or HUVECs and microRNA was purified using the mirVanaTM miRNA Isolation Kit (Ambion). microRNA obtained from 10 µg of total RNA was labeled using the mirVanaTM miRNA Labeling Kit (Ambion) and fluorescent Cy3 (Molecular Probes), and hybridized to the Ambion mirVanaTM miRNA Bioarray (1566 v.1). Hybridized mirVana miRNA Bioarrays were scanned and quantified by using ImaGene 5.5.4 (Bio Discovery). Resulted signal intensities were background corrected and then normalized using variance stabilization normalization. (Huber, 2002).

Dataset Information

The Apaf-1-binding protein Aven is cleaved by Cathepsin D to unleash its anti-apoptotic potential.

Publications

The Apaf-1-binding protein Aven is cleaved by Cathepsin D to unleash its anti-apoptotic potential.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets