Ubc13, a ubiquitin-conjugating enzyme (Ubc), requires the presence of a Ubc variant (Uev) for polyubiquitination. Uevs, although resembling Ubc in sequence and structure, lack the active site cysteine residue and are catalytically inactive. The yeast Uev (Mms2) incites noncanonical Lys63-linked polyubiquitination by Ubc13, whereas the increased diversity of Uevs in higher eukaryotes suggests an unexpected complication in ubiquitination. In this study, we demonstrate that divergent activities of mammalian Ubc13 rely on its pairing with either of two Uevs, Uev1A or Mms2. Structurally, we demonstrate that Mms2 and Uev1A differentially modulate the length of Ubc13-mediated Lys63-linked polyubiquitin chains. Functionally, we describe that Ubc13–Mms2 is required for DNA damage repair but not nuclear factor κB (NF-κB) activation, whereas Ubc13–Uev1A is involved in NF-κB activation but not DNA repair. Our finding suggests a novel regulatory mechanism in which different Uevs direct Ubcs to diverse cellular processes through physical interaction and alternative polyubiquitination.

MMI could not neutralize the diversity-limiting properties of academic scores as selection criteria to interview. Using academic scores in this way causes range restriction, counteracting attempts to enhance diversity using downstream admissions selection measures such as MMI. Diversity efforts should instead be focused upstream. These results lend further support for the development of pipeline programs.

SUMMARY The interference of IgM-class rheumatoid factor (RF) in the solid-phase radioimmunoassay (RIA) of rubella virus IgM antibodies was studied. Acute rubella infections did not significantly activate RF. False-positive rubella antibody results were obtained, however, when patients with raised RF levels were tested. If a low rubella IgG antibody titre was present, a high level of RF was required to cause a false-positive IgM result; conversely, in sera with high IgG titres, only a low level of RF was required for interference. Although the false-positive IgM titres obtained were generally low, they did show a positive correlation to both RF levels and rubella IgG titres. False-positive results were successfully avoided by removing the RF by absorption with heat-aggregated human gamma globulin. The absorption procedure did not affect true rubella IgM antibody titres.In modern virology and microbiology, human antibodies are, to an increasing degree, detected by immunoassays using marked anti-human immunoglobulins. An indirect fluorescent antibody technique (IFAT), an immunoperoxidase technique, an enzyme-linked immunosorbent assay, and a radioimmunoassay (RIA) have all been used in rubella serology (Haire and Hadden, 1970;Voller and Bidwell, 1975;Gerna and Chambers, 1976;Kalimo et al., 1976). A great advantage of these assays is the possibility of obtaining a rapid diagnosis of a recent infection by demonstrating specific IgM-class antibodies. However, in all assays which detect IgM antibodies by anti-human-IgM immunoglobulins, IgM-class rheumatoid factor (RF) is potentially capable of causing a false-positive IgM result, as has been clearly demonstrated in the case of the IFAT by Shirodaria et al. (1973).Preliminary work indicated that the solid-phase RIA method developed in our laboratory for detection of IgM antibodies against rubella virus (Kalimo et al., 1976;Meurman et al., 1977) is affected less by the presence of the RF than is the IFAT. More detailed studies on the effect of RF in Received for publication 7 December 1977 our IgM antibody RIA, however, required an equally sensitive method for determination of RF; therefore, a solid-phase RIA for IgM-RF was developed (Ziola et al., in press). Further investigations on the interference of RF in the solid-phase rubella IgM RIA were then undertaken. The results obtained are presented in this report. Material and methods SERUM SPECIMENSA total of 199 serum specimens were tested. These included 126 serial specimens from 28 patients with an acute rubella virus infection, 61 single serum specimens from patients with rheumatoid arthritis, and 10 single serum specimens from other patients having raised RF levels. In addition, two control specimens with low RF levels were used, one being negative for both rubella-specific IgG and IgM, and the other having a high rubella IgG antibody titre but no rubella IgM antibodies.RUBELLA IgG AND IgM ANTIBODY RIA

Distinct microbial ecosystems have evolved to meet the challenges of indoor environments, shaping the microbial communities that interact most with modern human activities. Microbial transmission in food-processing facilities has an enormous impact on the qualities and healthfulness of foods, beneficially or detrimentally interacting with food products. To explore modes of microbial transmission and spoilage-gene frequency in a commercial food-production scenario, we profiled hop-resistance gene frequencies and bacterial and fungal communities in a brewery. We employed a Bayesian approach for predicting routes of contamination, revealing critical control points for microbial management. Physically mapping microbial populations over time illustrates patterns of dispersal and identifies potential contaminant reservoirs within this environment. Habitual exposure to beer is associated with increased abundance of spoilage genes, predicting greater contamination risk. Elucidating the genetic landscapes of indoor environments poses important practical implications for food-production systems and these concepts are translatable to other built environments.DOI: http://dx.doi.org/10.7554/eLife.04634.001

Multiple sclerosis (MS) and matched control sera had similar antibody titers to coronaviruses OC43 and 229E when tested by a radioimmunoassay method. In contrast, cerebrospinal fluid from MS patients contained coronavirus antibodies more frequently and in higher titers than matched controls. Intrathecal antibody synthesis to OC43 and 229E viruses was detected in 41% (9/22) and 26% (7/27) of MS patients, respectively, but was not found in any of the neurologic control patients. This intrathecal antibody synthesis may mean that coronaviruses play an etiologic or pathogenic role in MS. Alternatively, intrathecal synthesis of coronavirus antibodies may be but part of a generalized and variable intrathecal antibody synthesis that is typical for MS patients.

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Three endogenous translesion DNA polymerases are sequentially assembled to the stalled replication site in the form of UV-induced nuclear foci. Detailed supporting evidence is given for the polymerase switch model.

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