Gene cloning and expression analysis of ubiquitin derived from Musca domestica.
Ubiquitin (Ub) is a highly conserved 8-kDa protein that was first identified as a tag for protein degradation. Recently, its role in nonproteolytic cellular processes such as DNA repair and endocytosis has also been reported. An ubiquitin-fusion gene was cloned from Musca domestica. The complete length of this ubiquitin-fusion gene is 531 bp, of which 471 bp is an open reading frame (ORF) encoding a 156-amino acid peptide, and 60 bp is a 3'-untranslated region with the polyadenylation sequence AATAAA and a poly(A) tail. The ubiquitin-fusion protein includes an ubiquitin monomer of 76 amino acids with a 6-amino acid motif (LRLRGG) and 3 conserved lysine functional sites, which participate in the formation of the ubiquitin-protease complex. The ubiquitin-fusion protein also contains an 80-amino acid carboxyl extension protein, namely, ribosomal protein S27 with a classical zinc finger motif C-X(4)-C-X(14)-C-X(2)-C. Because of its carboxyl extension protein S27, the M. domestica ubiquitin-fusion protein was named Mub(S27). It has a predicted molecular weight of 18 kDa and a theoretical isoelectric point of 9.82. No signal peptides were predicted for the protein. Northern blot analysis revealed that Mub(S27) transcript level is higher at the embryo stage than that at any other developmental stages. When houseflies develop into 5-day pupae, the Ub mRNA level is relatively low. After infection with gram-negative and gram-positive bacteria, Mub(S27) transcript level was upregulated. Mub(S27) transcript level was also regulated by heat or cold stress.
Ren
Qian
Q
School of Life Sciences, Shandong University, Jinan, Shandong 250100, China.
Zhang
Wei
W
Zhao
Xiao-Fan
XF
Wang
Jin-Xing
JX
D000222:Adaptation, Physiological / Q000276:immunology*; D000595:Amino Acid Sequence; D000818:Animals; D001424:Bacterial Infections / Q000276:immunology / Q000378:metabolism; D001483:Base Sequence; D004926:Escherichia coli; D015870:Gene Expression; D006793:Houseflies / Q000382:microbiology / Q000502:physiology*; D008018:Life Cycle Stages / Q000502:physiology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013211:Staphylococcus aureus; D013696:Temperature; D025801:Ubiquitin / Q000235:genetics* / Q000378:metabolism
D025801:Ubiquitin