Adequate transport of large proteins that function in the nucleus is indis-pensable for cognate molecular events within this organelle. Selective pro-tein import into the nucleus requires nuclear localization signals (NLS)
that are recognized by importin receptors in the cytoplasm.
Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học quốc tế cung cấp cho các bạn kiến thức về ngành y đề tài: A Drosophila protein-interaction map centered on cell-cycle regulators...
Polyubiquitin receptors execute the targeting of polyubiquitylated proteins
to the 26S proteasome. In vitro studies indicate that disturbance of the
physiological balance among different receptor proteins impairs the prote-asomal degradation of polyubiquitylated proteins.
Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học Journal of Biology đề tài: Imp-L2, a putative homolog of vertebrate IGF-binding protein 7, counteracts insulin signaling in Drosophila and is essential for starvation resistance...
We observed previously that cisplatin-resistant HeLa cells were cross-resistant to UV light due to accumulation of DDB2, a protein implicated in DNA repair. More recently, we found that cFLIP, which represents an anti-apoptotic protein whose level is induced by DDB2, was implicated in preventing apoptosis induced by deathreceptor signaling. In the present study, we investigated whether DDB2 has a protective role against UV irradiation and whether cFLIP is also involved in this process. Methods: We explored the role of DDB2 in mediating UV resistance in both human cells and Drosophila.
The mitochondrial carriers are a family of transport proteins that shuttle
metabolites, nucleotides and cofactors across the inner mitochondrial mem-brane. The genome ofDrosophila melanogasterencodes at least 46 mem-bers of this family. Only five of these have been characterized, whereas the
transport functions of the remainder cannot be assessed with certainty.
Translin protein is highly conserved in eukaryotes. Human translin binds
both ssDNA and RNA. Its nucleic acid binding site results from a combina-tion of basic regions in the octameric structure. We report here the first bio-chemical characterization of wild-typeDrosophila melanogaster(drosophila)
translin and a chimeric translin, and present 3.5 A
resolution crystal struc-tures of drosophila P168S mutant translin from two crystal forms.
In insects, the functional molecules responsible for the taste system are still
obscure. The gene for a 28.5 kDa protein purified from taste sensilla of the
blowflyPhormia reginabelongs to a gene family that includestakeout of
Drosophila melanogaster. Molecular phylogenetic analysis revealed that the
PhormiaTakeout-like protein is most similar to the protein encoded by a
member of theDrosophila takeoutgene family, CG14661, whose expression
and function have not been identified yet.
Three point mutations R335S, L336V and V476L, distin-guish the sequence of a cytochrome P450CYP6A2 variant
assumed to be responsible for 1,1,1-trichloro-2,2-bis-(4¢-chlorophenyl)ethane (DDT) resistance in theRDDT
ofDrosophila melanogaster. To determine the impact of
each mutation on the function of CYP6A2, the wild-type
enzyme (CYP6A2wt) ofCyp6a2was expressed inEscheri-chia colias well as three variants carrying a single mutation,
the double mutant CYP6A2vSV and the triple mutant
CYP6A2vSVL. All CYP6A2 variants were less stable than
the CYP6A2wt protein. ...
Eukaryotic initiation factor (eIF) 4B is part of the protein
complex involved in the recognition and binding of mRNA
to the ribosome. Drosophila eIF4Bis a single-copy gene
that encodes two isoforms, termed eIF4B-L (52.2 kDa) and
eIF4B-S (44.2 kDa), generated as a result of the alternative
recognition of two polyadeynlation signals during tran-scription termination and subsequent alternative splicing of
the two pre-mRNAs. Both eIF4B mRNAs and proteins are
expressed during the entire embryogenesis and life cycle....
Mitochondrial biogenesis is a complex and highly regulated
process that requires the controlled expression of hundreds
of genes encoded in two separated genomes, namely the
nuclear and mitochondrial genomes. To identify regulatory
proteins involved in the transcriptional control of key nuc-lear-encoded mitochondrial genes, we have performed a
detailed analysis of the promoter region of theasubunit of
the Drosophila melanogasterF1F0
ATP synthase complex.
Follistatin-related protein (FRP)⁄follistatin-like 1 (FSTL1) is a member of the
follistatin protein family, all of which share a characteristic structure unit found
in follistatin, called the FS domain. Developmental studies have suggested that
FRP regulates organ tissue formation in embryos. Immunological studies
showed that FRP modifies joint inflammation in arthritic disease, and modu-lates allograft tolerance.
Calpain B is one of the two catalytically competent calpain (calcium-acti-vated papain) isoenzymes in Drosophila melanogaster. Because structural
predictions hinted at the presence of several potential phosphorylation sites
in this enzyme, we investigated the in vitro phosphorylation of the recombi-nant protein by protein kinase A as well as by the extracellular signal-regu-lated protein kinases (ERK) 1 and 2.
The unique ability of mammals to detect and discriminate between thou-sands of different odorant molecules is governed by the diverse array of
olfactory receptors expressed by olfactory sensory neurons in the nasal
epithelium. Olfactory receptors consist of seven transmembrane domain G
protein-coupled receptors and comprise the largest gene superfamily in
the mammalian genome.
Enhancer of rudimentary homolog (Drosophila) (ERH) is a small, highly
conserved, nuclear protein with a unique three-dimensional structure,
whose gene has been identified in animals, plants and protists, but not in
The humanmyeloid leukemia factor 1(hMLF1) gene was first identified as
anNPM–hMLF1fusion gene produced by chromosomal translocation. In
Drosophila, dMLF has been identified as a protein homologous to hMLF1
and hMLF2, which interacts with various factors involved in transcrip-tional regulation.
Four distinct eukaryotic initiation factor 2a(eIF2a)kinases
phosphorylate eIF2aat S51and regulateprotein synthesis in
response to various environmental stresses. These are the
hemin-regulated inhibitor (HRI), the interferon-inducible
dsRNA-dependent kinase (PKR), the endoplasmic reticu-lum (ER)-resident kinase (PERK) and the GCN2 protein
kinase. Whereas HRI and PKR appear to be restricted to
mammalian cells, GCN2 and PERK seem to be widely
distributed in eukaryotes.
A Drosophila melanogaster cDNA clone (GH01916)
encoding a putative 723-residue long (82 kDa) protein
(CG 7415) and displaying 50% identity with mammalian
cytosolic dipeptidyl aminopeptidase (DPP) III was func-tionally expressed in Schneider S2
cells. Immunocytochemi-cal studies using anti-(rat liver DPP III) Ig indicated the
expression of this putative DPP III at the outer cell mem-brane and into the cytosol of transfected cells.
A putativeDrosophilanucleotide sugar transporter was
characterized and shown to be theDrosophilahomologue of
the human UDP-Gal transporter (hUGT). When the
Drosophila melanogasterUDP-Gal transporter (DmUGT)
was expressed in mammalian cells, the transporter protein
was localized in the Golgi membranes and complemented
the UDP-Gal transport de®ciency of Lec8 cells but not the
CMP-Sia transport de®ciency of Lec2 cells.