Role of the HCF-1 Basic Region in Sustaining Cell Proliferation

BACKGROUND: The human herpes simplex virus-associated host cell factor 1 (HCF-1) is a conserved human transcriptional co-regulator that links positive and negative histone modifying activities with sequence-specific DNA-binding transcription factors. It is synthesized as a 2035 amino acid precursor that is cleaved to generate an amino- (HCF-1(N)) terminal subunit, which promotes G1-to-S phase progression, and a carboxy- (HCF-1(C)) terminal subunit, which controls multiple aspects of cell division during M phase. The HCF-1(N) subunit contains a Kelch domain that tethers HCF-1 to sequence-specific DNA-binding transcription factors, and a poorly characterized so called "Basic" region (owing to a high ratio of basic vs. acidic amino acids) that is required for cell proliferation and has been shown to associate with the Sin3 histone deacetylase (HDAC) component. Here we studied the role of the Basic region in cell proliferation and G1-to-S phase transition assays. METHODOLOGY/PRINCIPAL FINDINGS: Surprisingly, much like the transcriptional activation domains of sequence-specific DNA-binding transcription factors, there is no unique sequence within the Basic region required for promoting cell proliferation or G1-to-S phase transition. Indeed, the ability to promote these activities is size dependent such that the shorter the Basic region segment the less activity observed. We find, however, that the Basic region requirements for promoting cell proliferation in a temperature-sensitive tsBN67 cell assay are more stringent than for G1-to-S phase progression in an HCF-1 siRNA-depletion HeLa-cell assay. Thus, either half of the Basic region alone can support G1-to-S phase progression but not cell proliferation effectively in these assays. Nevertheless, the Basic region displays considerable structural plasticity because each half is able to promote cell proliferation when duplicated in tandem. Consistent with a potential role in promoting cell-cycle progression, the Sin3a HDAC component can associate independently with either half of the Basic region fused to the HCF-1 Kelch domain. CONCLUSIONS/SIGNIFICANCE: While conserved, the HCF-1 Basic region displays striking structural flexibility for controlling cell proliferation

Clinical and molecular genetic features of pulmonary hypertension in patients with hereditary hemorrhagic telangiectasia

BACKGROUND: Most patients with familial primary pulmonary hypertension have defects in the gene for bone morphogenetic protein receptor II (BMPR2), a member of the transforming growth factor beta (TGF-beta) superfamily of receptors. Because patients with hereditary hemorrhagic telangiectasia may have lung disease that is indistinguishable from primary pulmonary hypertension, we investigated the genetic basis of lung disease in these patients. METHODS: We evaluated members of five kindreds plus one individual patient with hereditary hemorrhagic telangiectasia and identified 10 cases of pulmonary hypertension. In the two largest families, we used microsatellite markers to test for linkage to genes encoding TGF-beta-receptor proteins, including endoglin and activin-receptor-like kinase 1 (ALK1), and BMPR2. In subjects with hereditary hemorrhagic telangiectasia and pulmonary hypertension, we also scanned ALK1 and BMPR2 for mutations. RESULTS: We identified suggestive linkage of pulmonary hypertension with hereditary hemorrhagic telangiectasia on chromosome 12q13, a region that includes ALK1. We identified amino acid changes in activin-receptor-like kinase 1 that were inherited in subjects who had a disorder with clinical and histologic features indistinguishable from those of primary pulmonary hypertension. Immunohistochemical analysis in four subjects and one control showed pulmonary vascular endothelial expression of activin-receptor-like kinase 1 in normal and diseased pulmonary arteries. CONCLUSIONS: Pulmonary hypertension in association with hereditary hemorrhagic telangiectasia can involve mutations in ALK1. These mutations are associated with diverse effects, including the vascular dilatation characteristic of hereditary hemorrhagic telangiectasia and the occlusion of small pulmonary arteries that is typical of primary pulmonary hypertension

Taking lemons for a trial run: does type of job exit affect the risk of entering fixed-term employment in Germany?

A central argument for the deregulation of employment contracts is that fixed-term contracts boost employment of jobseekers with uncertain productivity by giving employers a tool to screen such applicants over a longer period of time before permanent hire. We test this proposition by comparing the risk of entering fixed-term employment for individually laid-off workers with that for individuals who have left their previous job for other reasons. This strategy is based on the assumption that in the German context individual lay-offs create uncertainty about jobseekers’ productivity. We use data on work exits and subsequent labour market re-entry of the prime-age workforce in Germany from waves 2000–2013 of the Socio-Economic Panel. Our results show that the risk of fixed-term employment is substantively smaller after voluntary job exits but reveal only a small and statistically insignificant risk difference between individual lay-offs and workplace closures after adjusting for differences in socio-economic background and characteristics of the previous job. These findings challenge the view that employers use fixed-term contracts as an instrument to screen specific groups of workers whose productivity is highly uncertain, at least with regard to recent career disruptions

Reflections: Students\u27 Tribute to Stan Kuczaj (1950-2016)

On April 14th, 2016, Animal Behavior and Cognition lost its Editor-in-Chief. But the scientific community and the friends and colleagues of Stanley ‘Stan’ Kuczaj III lost so much more. As many know, Stan began his career in Developmental Psychology, making enormous contributions in the area of language development, but became best known for his many innovative contributions in the area of marine mammal behavior. Stan founded Animal Behavior and Cognition because he was deeply passionate about research with a broad range of topics concerning animal behavior, animal cognition, and animal welfare. He was equally passionate about the idea that science should be accessible to all, and that accessibility should not come at a financial burden to researchers. The current editorial team is committed to carrying on Stan’s vision for the journal, and we believe that its continuation will pay homage to Stan as a researcher, and as a leader within the scientific community. However, for the next few pages, we wish to pay special tribute to Stan as a mentor, as this role was perhaps the one that was most pivotal in defining who he was as a scientist, colleague, and friend. We take comfort in the fact that Stan’s memory will live on in the legacy of his mentees, many of whom became cherished friends and colleagues. Below you will find reflections from several of these former students who were given the difficult task of trying to summarize the most meaningful aspect of Stan’s influence on their personal and professional development. Although no few words could summarize the impact of someone as enigmatic as Stan, we hope that these reflections will contribute to a full and nuanced tribute to the man he was

Germline mutations in PMS2 and MLH1 in individuals with solitary loss of PMS2 expression in colorectal carcinomas from the Colon Cancer Family Registry Cohort

Immunohistochemistry for DNA mismatch repair proteins is used to screen for Lynch syndrome in individuals with colorectal carcinoma (CRC). Although solitary loss of PMS2 expression is indicative of carrying a germline mutation in PMS2, previous studies reported MLH1 mutation in some cases. We determined the prevalence of MLH1 germline mutations in a large cohort of individuals with a CRC demonstrating solitary loss of PMS2 expression

Differentiated thyroid carcinoma in children and adolescents

From 1936 to 1990, 89 children and adolescents (72 girls and 17 boys) were treated for differentiated thyroid carcinoma at the University of Michigan Medical Center; 58 of these patients were first reported in 1971. Thirty (34%) patients had previously received external irradiation to the head and neck, although only 1 (3%) patient of the last 33 patients seen had this history. Patients first presenting from 1971 to 1990 had less advanced disease than those seen earlier. Also, during this time period, the rate of initial palpable cervical adenopathy fell from 63% to 36%, local infiltration of primary cancer from 31% to 6%, and initial pulmonary metastases from 19% to 6%. The incidence of cervical nodal metastases has remained 88% for 54 years. Papillary or the follicular variant of papillary carcinoma was found in 93% of all patients. Seventy-nine (89%) patients had total or completion total thyroidectomy. Surgical management of lymphatic metastases varied from regional excision of nodes to radical neck dissection. The overall rate of permanent accidental recurrent laryngeal nerve palsy and hypoparathyroidism was 4.5%, although neither has occurred in a child or adolescent undergoing surgery at the center in the past 25 years. The most recent 33 patients had a low rate of local/regional persistence or recurrence. Cervical nodal persistence occurred in 21%; there were no thyroid recurrences. Eighty-two percent of patients received 131 I. The long-term mortality rate was 2.2%. We continue to advocate total thyroidectomy, cervical lymph node dissection, and postoperative 131 I therapy as the most conservative treatment regimen for children with differentiated thyroid carcinoma. Entre 1936 et 1990, 89 enfants et adolescents (72 filles et 17 garons) ont été traités pour cancer différencie de la thyroïde au Centre Médical de l'Université de Michigan. Cinquante huit d'entre eux ont fait l'objet d'une publication en 1971. Trente de ces patients (34%) avaient eu une radiothérapie externe au niveau de la tête et/ou du cou, mais ce facteur n'a été retrouvé que chez un des 33 derniers patients (3%). Les patients vus entre 1971 et 1990 avaient une maladie moins avancée. Pendant cette période, le taux d'adénopathies cervicales palpables est passée de 63 à 36%; le pourcentage de patients ayant une infiltration locale, de 31 à 6%, et celui de métastases pulmonaires de 19 à 6%. L'incidence des métastases ganglionnaires cervicales, par contre, est restée de 88% depuis 54 ans. Le cancer était papillaire ou folliculaire dans 93% des cas. Soixante-neuf patients (89%) ont eu une thyroïdectomie totale, soit d'embl%ee soit secondairement. La thérapeutique des métastases ganglionnaires a varié depuis l'exérèse régionale et le curage ganglionnaire cervical. Le taux global de paralysie récurrentielle et de l'hypoparathyroïde était de 4.5%, mais aucune de ces deux complications n'a été observée pour les enfants opérés dans notre centre au cours des 25 dernières années. Parmi les 33 derniers patients, le taux de tissu résiduel ou de récidive était bas. Dans 21% des cas, il persistait du tissu néoplasique après chirurgie, sans récidive. Quatre-vingt pour cent de ces patients ont eu un traitement par l'iode 131. La mortalité à distance était de 2.2%. Nous continuous de recommander une thyroïdectomie totale, une lymphadénectomie cervicale et une iodothérapie post-opératoire par l'iode 131 comme le traitement les plus conservateurs du cancer différencié de la thyroïde chez l'enfant. Ochenta y nueve niños y adolescentes (72 de sexo femenino y 17 de sexo masculino) fuiron tratados por carcinoma tiroideo diferenciado en el Centro Médico de la Universidad de Michigan; 58 de estos pacientes fueron reportados por primera vez en 1971. Treinta pacientes (34%) tenían historia de irradiación a la cabeza y el cuello; sin embargo, solamente uno de los últimos 33 (3%) presentó tal historia. Los pacientes vistos entre 1971 y 1990 exhibían enfermedad menos avanzada que aquellos vistos previamente. Así mismo, la incidencia de adenopatías cervicales palpables descendió de 63% a 36%, la de infiltración local por cáncer primario de 31% a 6% y la de metástasis pulmonares iniciales de 19% a 6%. La incidencia de metástasis ganglionares cervicales se ha mantenido en 88% por 54 años. La variante papilar o folicular del carcinoma papilar se encontró en 93% de los pacientes de la serie. Setenta y nueve pacientes (89%) fueron sometidos a toroidectomía total o a reoperación para completar la tiroidectomía total. El manejo quirúrgico de las metástasis linfáticas varió desde la resección regional de los ganglios hasta la disección radical del cuello. La tasa global de lesión accidental, permanente o temporal, del nervio recurrente laríngeo y de hopoparatiroidismo fue 4.5%, aunque ninguna de estas complicaciones ha ocurrido en un niño o en un adolescente sometido a cirugía en nuestro centro médico en los últimos 25 años. Los últimos 33 pacientes exhibieron una tasa reducida de persistencia o de recurrencia local/regional. La persistencia ganglionar cervical se presentó en 21% de los casos; no hubo recurrencias tiroideas. Ochenta y dos por ciento de los pacientes recibió 131 I. La tassa de mortalidad a largo plazo fui 2.2%. Nuestro grupo continúa preconizando tiroidectomía total, disección ganglionar cervical y terapia postoperatoria con 131 I como la modalidad terapéutica más conservadora en carcinoma diferenciado de la glándula tiroidea en la niñez.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41290/1/268_2005_Article_BF02067317.pd

The Local Role in Homeland Security

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73848/1/j.1540-5893.2005.00236.x.pd

DMSO and Betaine Greatly Improve Amplification of GC-Rich Constructs in De Novo Synthesis

In Synthetic Biology, de novo synthesis of GC-rich constructs poses a major challenge because of secondary structure formation and mispriming. While there are many web-based tools for codon optimizing difficult regions, no method currently exists that allows for potentially phenotypically important sequence conservation. Therefore, to overcome these limitations in researching GC-rich genes and their non-coding elements, we explored the use of DMSO and betaine in two conventional methods of assembly and amplification. For this study, we compared the polymerase (PCA) and ligase-based (LCR) methods for construction of two GC-rich gene fragments implicated in tumorigenesis, IGF2R and BRAF. Though we found no benefit in employing either DMSO or betaine during the assembly steps, both additives greatly improved target product specificity and yield during PCR amplification. Of the methods tested, LCR assembly proved far superior to PCA, generating a much more stable template to amplify from. We further report that DMSO and betaine are highly compatible with all other reaction components of gene synthesis and do not require any additional protocol modifications. Furthermore, we believe either additive will allow for the production of a wide variety of GC-rich gene constructs without the need for expensive and time-consuming sample extraction and purification prior to downstream application