LZ-FYVE: a novel developmental stage-specific leucine zipper, FYVE-finger protein.
We describe the molecular cloning and characterization of LZ-FYVE, a novel embryonic factor that possesses two leucine zipper motifs and a FYVE-finger domain. A partial clone of LZ-FYVE, encoding a functional leucine zipper domain, was initially isolated from a mouse embryo cDNA library by virtue of its interaction in the yeast two-hybrid system with the transcription factor ATF-2. The LZ-FYVE protein demonstrated mouse embryo-specific expression by Northern blot analysis and was detected as a nuclear protein at very restricted periods (12--14 days post-coitus) in specific tissues during embryogenesis. In particular, LZ-FYVE protein was notable in embryonic lung, cartilage, and otic capsule. Structural analysis of the deduced, full-length LZ-FYVE amino acid sequence revealed two N-terminal leucine zipper domains as well as a C-terminal FYVE-finger domain. The FYVE-finger domains specifically recognized phosphatidylinositol 3-phosphate and have been previously described only in cytoplasmic proteins involved in endosomal membrane fusion, vesicular trafficking, or organelle-specific targeting. While LZ-FYVE may have endosomal functions in the cytoplasm, because LZ-FYVE is present in the nucleus at early stages of embryonic development, it is likely that LZ-FYVE has a nuclear function.
Dunkelberg
J C
JC
Department of Medicine, University of Colorado Health Sciences Center, Denver, Colorado 80220, USA.
Gutierrez-Hartmann
A
A
D051698:Activating Transcription Factor 2; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D002454:Cell Differentiation; D002460:Cell Line; D019902:Chondrocytes / Q000166:cytology; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism*; D015870:Gene Expression; D006367:HeLa Cells; D006801:Humans; D016350:Leucine Zippers; D051379:Mice; D008809:Mice, Inbred C3H; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology; D014157:Transcription Factors / Q000378:metabolism*
C497105:ATF2 protein, human; D051698:Activating Transcription Factor 2; C497106:Atf2 protein, mouse; D017362:Cyclic AMP Response Element-Binding Protein; D009687:Nuclear Proteins; C434671:Rufy2 protein, mouse; D014157:Transcription Factors