A novel adenovirus E1B19K-binding protein B5 inhibits apoptosis induced by Nip3 by forming a heterodimer through the C-terminal hydrophobic region

N Ohi; A Tokunaga; H Tsunoda; K Nakano; K Haraguchi; K Oda; N Motoyama; T Nakajima

doi:10.1038/sj.cdd.4400493

A novel adenovirus E1B19K-binding protein B5 inhibits apoptosis induced by Nip3 by forming a heterodimer through the C-terminal hydrophobic region

Cell Death Differ. 1999 Apr;6(4):314-25. doi: 10.1038/sj.cdd.4400493.

Authors

N Ohi¹, A Tokunaga, H Tsunoda, K Nakano, K Haraguchi, K Oda, N Motoyama, T Nakajima

Affiliation

¹ Department of Biological Science and Technology, Science University of Tokyo, Noda, Japan.

PMID: 10381623
DOI: 10.1038/sj.cdd.4400493

Abstract

The adenovirus E1B19K protein inhibits apoptosis induced by E1A and other divergent signals. The cellular proteins that interact with E1B19K have been analyzed by isolating cDNA clones by the yeast two hybrid system. One of these clones encodes B5 which consists of 219 amino acid residues and contains the putative BH3 and transmembrane regions. B5 binds strongly to Nip3 and itself, weakly to E1B19K, but not to Bcl-2 and localizes in nuclear envelope, endoplasmic reticulum and mitochondria. B5 has sequence homology with Nip3 in the middle and C-terminal regions, but not in the N-terminal region. Unlike other E1B19K binding BH3 proteins so far characterized, B5 does not induce apoptosis, but inhibits apoptosis induced by Nip3. However the deletion mutant B5Delta1-31 lacking the N-terminus does induce apoptosis, although weaker than does Nip3, suggesting that the N-terminal region is masking the apoptosis-inducing capacity of B5.

MeSH terms

Adaptor Proteins, Signal Transducing*
Adenovirus E1B Proteins / chemistry
Adenovirus E1B Proteins / genetics
Adenovirus E1B Proteins / metabolism*
Animals
Apoptosis / physiology*
Base Sequence
Blotting, Western
COS Cells
Carcinoma, Squamous Cell
Carrier Proteins / analysis
Carrier Proteins / chemistry*
Carrier Proteins / genetics*
DNA, Complementary
Dimerization
Flow Cytometry
Gene Expression / physiology
Humans
Membrane Proteins / chemistry
Membrane Proteins / genetics
Membrane Proteins / metabolism*
Molecular Sequence Data
Protein Binding / physiology
Protein Structure, Tertiary
Proto-Oncogene Proteins*
RNA, Messenger / analysis
Sequence Homology, Amino Acid
Subcellular Fractions / chemistry
Tumor Cells, Cultured / cytology
Tumor Cells, Cultured / metabolism
Tumor Cells, Cultured / virology
Tumor Suppressor Proteins*
Viral Proteins*
Yeasts / genetics

Substances

Adaptor Proteins, Signal Transducing
Adenovirus E1B Proteins
BNIP3 protein, human
BNIP3L protein, human
Carrier Proteins
DNA, Complementary
E1B19K-binding protein B5
Membrane Proteins
Proto-Oncogene Proteins
RNA, Messenger
Tumor Suppressor Proteins
Viral Proteins