The RAD6 gene of yeast: A link between DNA repair, chromosome structure and protein degradation?

1988 ◽  
Vol 27 (4) ◽  
pp. 277-286 ◽  
Author(s):  
W. Siede
Keyword(s):  
Dna Repair ◽  
Protein Degradation ◽  
Chromosome Structure ◽  
Rad6 Gene

scholarly journals Domains required for dimerization of yeast Rad6 ubiquitin-conjugating enzyme and Rad18 DNA binding protein.

1997 ◽  
Vol 17 (8) ◽  
pp. 4536-4543 ◽  
Author(s):  
V Bailly ◽  
S Prakash ◽  
L Prakash
Keyword(s):  
Dna Binding ◽  
Protein Degradation ◽  
Binding Activity ◽  
Helix Loop Helix ◽  
Dna Binding Activity ◽  
C Terminus ◽  
Rad6 Gene ◽  
Ubiquitin Conjugating Enzyme ◽  
Dependent Protein ◽  
Conjugating Enzyme

The RAD6 gene of Saccharomyces cerevisiae encodes a ubiquitin-conjugating enzyme required for postreplicational repair of UV-damaged DNA and for damage-induced mutagenesis. In addition, Rad6 functions in the N end rule pathway of protein degradation. Rad6 mediates its DNA repair role via its association with Rad18, whose DNA binding activity may target the Rad6-Rad18 complex to damaged sites in DNA. In its role in N end-dependent protein degradation, Rad6 interacts with the UBR1-encoded ubiquitin protein ligase (E3) enzyme. Previous studies have indicated the involvement of N-terminal and C-terminal regions of Rad6 in interactions with Ubr1. Here, we identify the regions of Rad6 and Rad18 that are involved in the dimerization of these two proteins. We show that a region of 40 amino acids towards the C terminus of Rad18 (residues 371 to 410) is sufficient for interaction with Rad6. This region of Rad18 contains a number of nonpolar residues that have been conserved in helix-loop-helix motifs of other proteins. Our studies indicate the requirement for residues 141 to 149 at the C terminus, and suggest the involvement of residues 10 to 22 at the N terminus of Rad6, in the interaction with Rad18. Each of these regions of Rad6 is indicated to form an amphipathic helix.

Chronic Myeloid Leukemia with Variant t(9;22) Shows Dysregulated Expression of Genes Included in Pivotal Cellular Pathways

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1674-1674
Author(s):  
Francesco Albano ◽  
Luisa Anelli ◽  
Antonella Zagaria ◽  
Nicoletta Coccaro ◽  
Luciana Impera ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Cycle ◽  
Dna Repair ◽  
Chronic Myeloid Leukemia ◽  
Protein Degradation ◽  
Myeloid Leukemia ◽  
Cell Cycle Progression ◽  
Molecular Response ◽  
Cycle Progression ◽  
Functional Relationships

Abstract Abstract 1674 The t(9;22)(q34;q11) generating the Philadelphia chromosome and the BCR/ABL1 fusion gene represents the cytogenetic hallmark of chronic myeloid leukemia (CML). About 5–10% of CML cases show variant translocations with the involvement of other chromosomes in addition to chromosomes 9 and 22. The greater frequency of occurrence of genomic microdeletions proximally to ABL1 or distally to BCR has been reported in CML cases with variant translocations (30–40%) than in cases with a classic t(9;22) (10–18%). The prognostic significance of variant t(9;22) was unclear and debated in the pre-imatinib era, whereas recent studies of large CML series showed that the presence of variant translocations has no impact on the cytogenetic and molecular response or on prognosis (Marzocchi et al. Blood 2011,117:6793-800). However, the molecular bases of differences between CML patients with classic and variant t(9;22) have never been elucidated. Here we report a gene expression profile analysis of 8 CML cases with variant t(9;22) and 12 patients with a classic t(9;22). RNA samples were extracted from bone marrow cells and hybridized on the Agilent SurePrint G3 Human GE 8×60K Microarray slide (Agilent Technologies). Ingenuity Pathways Analysis (IPA, www.ingenuity.com) software was used to provide an accurate biological and statistical analysis of microarray experimental data revealing functional relationships among the identified genes. Gene expression analysis identified a 59 gene set able to distinguish the two CML subsets. These genes are mostly involved in the development of the hematological system and in the occurrence of hematological diseases. Forty-five out of 59 (76%) genes were up-regulated, causing the probable activation of different molecular mechanisms such as cellular responses to stimuli, protein degradation, DNA repair, cell cycle progression. IPA analysis revealed that most of the dysregulated genes are included in a network where they are functionally linked to MAPK p38, AKT, and NFKB. Moreover, several genes play a role in cytoskeleton organization (WIPF1), in signal transduction and cell cycle progression (TRIB1, PDE4B, PTK2B, PLK3), in regulation of apoptosis (ZFAND5, STK17B), and in protein degradation (ZFAND5, SNRPG). On the contrary, among the downregulated genes, 5 (BCDIN3D, TMEM68, HILPDA, TMEM68, and C17orf61) establish direct interactions with ubiquitin C (UBC), a crucial gene involved in different intracellular mechanisms such as protein degradation, DNA repair, cell cycle regulation, and the regulation of other signaling pathways. In conclusion, gene expression profiling in cases with variant t(9;22) revealed biological differences in this CML subset. Our data show an overall deregulation of genes involved in hematological system development and in cell proliferation signaling pathway. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Centrin/Cdc31 Is a Novel Regulator of Protein Degradation

2007 ◽  
Vol 28 (5) ◽  
pp. 1829-1840 ◽  
Author(s):  
Li Chen ◽  
Kiran Madura
Keyword(s):  
Dna Repair ◽  
Protein Degradation ◽  
Calcium Binding ◽  
Excision Repair ◽  
Uv Light ◽  
Dual Function ◽  
Highly Sensitive ◽  
Ef Hand ◽  
Carboxy Terminal ◽  
First Time

ABSTRACT Rad23 is required for efficient protein degradation and performs an important role in nucleotide excision repair. Saccharomyces cerevisiae Rad23, and its human counterpart (hHR23), are present in a complex containing the DNA repair factor Rad4 (termed XPC, for xeroderma pigmentosum group C, in humans). XPC/hHR23 was also reported to bind centrin-2, a member of the superfamily of calcium-binding EF-hand proteins. We report here that yeast centrin, which is encoded by CDC31, is similarly present in a complex with Rad4/Rad23 (called NEF2). The interaction between Cdc31 and Rad23/Rad4 varied by growth phase and reflected oscillations in Cdc31 levels. Strikingly, a cdc31 mutant that formed a weaker interaction with Rad4 showed sensitivity to UV light. Based on the dual function of Rad23, in both DNA repair and protein degradation, we questioned if Cdc31 also participated in protein degradation. We report here that Cdc31 binds the proteasome and multiubiquitinated proteins through its carboxy-terminal EF-hand motifs. Moreover, cdc31 mutants were highly sensitive to drugs that cause protein damage, failed to efficiently degrade proteolytic substrates, and formed altered interactions with the proteasome. These findings reveal for the first time a new role for centrin/Cdc31 in protein degradation.

scholarly journals A ubiquitin mutant with specific defects in DNA repair and multiubiquitination.

1995 ◽  
Vol 15 (3) ◽  
pp. 1265-1273 ◽  
Author(s):  
J Spence ◽  
S Sadis ◽  
A L Haas ◽  
D Finley
Keyword(s):  
Dna Repair ◽  
Protein Conjugates ◽  
Dna Damaging Agents ◽  
Rad6 Gene ◽  
Ubiquitin Conjugating Enzyme ◽  
Alternate Forms ◽  
Induced Mutagenesis ◽  
Type Rate ◽  
Wild Type Rate

The degradation of many proteins involves the sequential ligation of ubiquitin molecules to the substrate to form a multiubiquitin chain linked through Lys-48 of ubiquitin. To test for the existence of alternate forms of multiubiquitin chains, we examined the effects of individually substituting each of six other Lys residues in ubiquitin with Arg. Substitution of Lys-63 resulted in the disappearance of a family of abundant multiubiquitin-protein conjugates. The UbK63R mutants were not generally impaired in ubiquitination, because they grew at a wild-type rate, were fully proficient in the turnover of a variety of short-lived proteins, and exhibited normal levels of many ubiquitin-protein conjugates. The UbK63R mutation also conferred sensitivity to the DNA-damaging agents methyl methanesulfonate and UV as well as a deficiency in DNA damage-induced mutagenesis. Induced mutagenesis is mediated by a repair pathway that requires Rad6 (Ubc2), a ubiquitin-conjugating enzyme. Thus, the UbK63R mutant appears to be deficient in the Rad6 pathway of DNA repair. However, the UbK63R mutation behaves as a partial suppressor of a rad6 deletion mutation, indicating that an effect of UbK63R on repair can be manifest in the absence of the Rad6 gene product. The UbK63R mutation may therefore define a new role of ubiquitin in DNA repair. The results of this study suggest that Lys-63 is used as a linkage site in the formation of novel multiubiquitin chain structures that play an important role in DNA repair.

scholarly journals Structure of HIV-1 Vpr in complex with the human nucleotide excision repair protein hHR23A

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
In-Ja L. Byeon ◽  
Guillermo Calero ◽  
Ying Wu ◽  
Chang H. Byeon ◽  
Jinwon Jung ◽  
...  
Keyword(s):  
Dna Repair ◽  
Protein Degradation ◽  
Nucleotide Excision Repair ◽  
Excision Repair ◽  
Three Dimensional ◽  
Large Family ◽  
Repair Protein ◽  
Nucleotide Excision ◽  
Hiv 1 ◽  
Nucleotide Excision Repair Protein

AbstractHIV-1 Vpr is a prototypic member of a large family of structurally related lentiviral virulence factors that antagonize various aspects of innate antiviral immunity. It subverts host cell DNA repair and protein degradation machineries by binding and inhibiting specific post-replication repair enzymes, linking them via the DCAF1 substrate adaptor to the Cullin 4 RING E3 ligase (CRL4DCAF1). HIV-1 Vpr also binds to the multi-domain protein hHR23A, which interacts with the nucleotide excision repair protein XPC and shuttles ubiquitinated proteins to the proteasome. Here, we report the atomic resolution structure of Vpr in complex with the C-terminal half of hHR23A, containing the XPC-binding (XPCB) and ubiquitin-associated (UBA2) domains. The XPCB and UBA2 domains bind to different sides of Vpr’s 3-helix-bundle structure, with UBA2 interacting with the α2 and α3 helices of Vpr, while the XPCB domain contacts the opposite side of Vpr’s α3 helix. The structure as well as biochemical results reveal that hHR23A and DCAF1 use overlapping binding surfaces on Vpr, even though the two proteins exhibit entirely different three-dimensional structures. Our findings show that Vpr independently targets hHR23A- and DCAF1- dependent pathways and highlight HIV-1 Vpr as a versatile module that interferes with DNA repair and protein degradation pathways.

PARP-mediated proteasome activation: A co-ordination of DNA repair and protein degradation?

BioEssays ◽  
2002 ◽  
Vol 24 (11) ◽  
pp. 1060-1065 ◽  
Author(s):  
Jenny Arnold ◽  
Tilman Grune
Keyword(s):  
Dna Repair ◽  
Protein Degradation

scholarly journals ROCC, a conserved region in cohesin's Mcd1 subunit, is essential for the proper regulation of the maintenance of cohesion and establishment of condensation

2014 ◽  
Vol 25 (16) ◽  
pp. 2351-2364 ◽  
Author(s):  
Thomas Eng ◽  
Vincent Guacci ◽  
Doug Koshland
Keyword(s):  
Dna Repair ◽  
Transcriptional Regulation ◽  
Amino Acid ◽  
Chromosome Structure ◽  
Regulatory Subunit ◽  
Linker Region ◽  
Functional Interactions ◽  
Chromatid Cohesion ◽  
Evolutionarily Conserved ◽  
Amino Acid Cluster

Cohesin helps orchestrate higher-order chromosome structure, thereby promoting sister chromatid cohesion, chromosome condensation, DNA repair, and transcriptional regulation. To elucidate how cohesin facilitates these diverse processes, we mutagenized Mcd1p, the kleisin regulatory subunit of budding yeast cohesin. In the linker region of Mcd1p, we identified a novel evolutionarily conserved 10–amino acid cluster, termed the regulation of cohesion and condensation (ROCC) box. We show that ROCC promotes cohesion maintenance by protecting a second activity of cohesin that is distinct from its stable binding to chromosomes. The existence of this second activity is incompatible with the simple embrace mechanism of cohesion. In addition, we show that the ROCC box is required for the establishment of condensation. We provide evidence that ROCC controls cohesion maintenance and condensation establishment through differential functional interactions with Pds5p and Wpl1p.

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