Journal
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
Volume 100, Issue 22, Pages 13042-13047Publisher
NATL ACAD SCIENCES
DOI: 10.1073/pnas.2135111100
Keywords
-
Categories
Funding
- NCI NIH HHS [P50 CA 92131, P50 CA092131, U01 CA084128, U01 CA 84128] Funding Source: Medline
- NIA NIH HHS [R01 AG020954, AG 20954] Funding Source: Medline
- NIDDK NIH HHS [P30 DK063491, P30 DK 063491] Funding Source: Medline
Ask authors/readers for more resources
Insulin-like growth factor-binding protein-3 (IGFBP-3) regulates IGF bioactivity and also independently modulates cell growth and survival. By using a yeast two-hybrid screen to identify IGFBP-3-interacting proteins, we cloned humanin (HN) as an IGFBP-3-binding partner. HN is a 24-aa peptide that has been shown to specifically inhibit neuronal cell death induced by familial Alzheimer's disease mutant genes and amyloid-beta (Abeta). The physical interaction of HN with IGFBP-3 was determined to be of high affinity and specificity and was confirmed by yeast mating, displaceable pull-down experiments with (His)-6-tagged HN, and ligand blot experiments. Coimmunoprecipitation of IGFBP-3 and HN from mouse testes confirmed the interaction in vivo. In crosslinking experiments, HN bound IGFBP-3 but did not compete with IGF-I-IGFBP-3 binding; competitive ligand dot blot experiments revealed the 18-aa heparin-binding domain of IGFBP-3 as the binding site for HN. Alanine scanning determined that F6A-HN mutant does not bind IGFBP-3. HN but not F6A-HN inhibited IGFBP-3-induced apoptosis in human glioblastoma-A172. In contrast, HN did not suppress IGFBP-3 response in SH-SY5Y neuroblastoma and mouse cortical primary neurons. In primary neurons, IGFBP-3 markedly potentiated HN rescue ability from Abeta(1-43) toxicity. In summary, we have identified an interaction between the survival peptide HN and IGFBP-3 that is pleiotrophic in nature and is capable of both synergistic and antagonistic interaction. This interaction may prove to be important in neurological disease processes and could provide important targets for drug development.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available