RESUMO
cDNAs encoding a novel DNA binding protein, termed Finb (finger protein in nuclear bodies) were molecularly cloned. The Finb protein consists of 1656 amino acids, containing 15 C2H2-type zinc fingers and three proline-rich regions. Finb efficiently activates transcription from the promoters of the metallothionein and thymidine kinase genes. The finb mRNA is ubiquitously expressed in various cell lines and tissues. The protein product is localized in nuclear bodies, whereas the N-terminally truncated protein spreads throughout the nucleus and cytoplasm. Further characterization of Finb would unravel an important role of nuclear body-involved transcriptional regulation.
Assuntos
Transativadores/genética , Dedos de Zinco/genética , Sequência de Aminoácidos , Animais , Western Blotting , Células COS , Núcleo Celular/genética , Núcleo Celular/metabolismo , Células Cultivadas , Cloranfenicol O-Acetiltransferase/metabolismo , Chlorocebus aethiops , Clonagem Molecular , Citoplasma/metabolismo , Fator de Crescimento Epidérmico/metabolismo , Técnica Indireta de Fluorescência para Anticorpo , Expressão Gênica , Genes erbB-2 , Humanos , Metalotioneína/genética , Dados de Sequência Molecular , Plasmídeos , Regiões Promotoras Genéticas , RNA Mensageiro/metabolismo , Alinhamento de Sequência , Timidina Quinase/genética , Transativadores/metabolismo , Transcrição Gênica , Ativação TranscricionalRESUMO
Microtubule-associated motor proteins are thought to be involved in spindle formation and chromosome movements in mitosis/meiosis. We have molecularly cloned cDNAs for a gene that codes for a novel member of the kinesin family of proteins. Nucleotide sequencing reveals that the predicted gene product is a 73 kDa protein and is related to some extent to the Drosophila node gene product, which is involved in chromosomal segregation during meiosis. A sequence similar to the microtubule binding motor domain of kinesin is present in the N-terminal half of the protein, and its ability to bind to microtubules is demonstrated. Furthermore we show that its C-terminal half contains a putative nuclear localization signal similar to that of Jun and is able to bind to DNA. Accordingly, the protein was termed Kid (kinesin-like DNA binding protein). Indirect immunofluorescence studies show that Kid colocalizes with mitotic chromosomes and that it is enriched in the kinetochore at anaphase. Thus, we propose that Kid might play a role(s) in regulating the chromosomal movement along microtubules during mitosis.
