The microtubule-associated protein, doublecortin-like kinase 1 (DCLK1), is highly expressed in a range of cancers and is a prominent therapeutic target for kinase inhibitors. The physiological roles of DCLK1 kinase activity and how it is regulated remain elusive. Here, we analyze the role of mammalian DCLK1 kinase activity in regulating microtubule binding. We find that DCLK1 autophosphorylates a residue within its C-terminal tail to restrict its kinase activity and prevent aberrant hyperphosphorylation within its microtubule-binding domain. Removal of the C-terminal tail or mutation of this residue causes an increase in phosphorylation within the doublecortin domains, which abolishes microtubule binding. Therefore, autophosphorylation at specific sites within DCLK1 have diametric effects on the molecule's association with microtubules. Our results suggest a mechanism by which DCLK1 modulates its kinase activity to tune its microtubule-binding affinity. These results provide molecular insights for future therapeutic efforts related to DCLK1's role in cancer development and progression.

BackgroundThe PacBio RS II provides for single molecule, real-time DNA technology to sequence genomes and detect DNA modifications. The starting point for high-quality sequence production is high molecular weight genomic DNA. To automate the library preparation process, there must be high-throughput methods in place to assess the genomic DNA, to ensure the size and amounts of the sheared DNA fragments and final library.FindingsThe library construction automation was accomplished using the Agilent NGS workstation with Bravo accessories for heating, shaking, cooling, and magnetic bead manipulations for template purification.The quality control methods from gDNA input to final library using the Agilent Bioanalyzer System and Agilent TapeStation System were evaluated.ConclusionsAutomated protocols of PacBio 10 kb library preparation produced libraries with similar technical performance to those generated manually. The TapeStation System proved to be a reliable method that could be used in a 96-well plate format to QC the DNA equivalent to the standard Bioanalyzer System results. The DNA Integrity Number that is calculated in the TapeStation System software upon analysis of genomic DNA is quite helpful to assure that the starting genomic DNA is not degraded. In this respect, the gDNA assay on the TapeStation System is preferable to the DNA 12000 assay on the Bioanalyzer System, which cannot run genomic DNA, nor can the Bioanalyzer work directly from the 96-well plates.

Introduction. Moraxella bovoculi is frequently isolated from the eyes of cattle with infectious bovine keratoconjunctivitis (IBK; pinkeye). As with M. bovis, which has been causally linked to IBK, M. bovoculi expresses an RTX (repeats in the structural toxin) cytotoxin that is related to M. bovis cytotoxin. Pilin, another pathogenic factor in M. bovis , is required for corneal attachment. Seven antigenically distinct pilin serogroups have been described in M. bovis . Hypothesis/Gap Statement. Multiple different serogroups exist amongst type IV pilin encoded by M. bovis , however, it is not known whether M. bovoculi exhibits a similar degree of diversity in type IV pilin that it encodes. Aim. This study was done to characterize a structural pilin (PilA) encoded by M. bovoculi isolated from cases of IBK to determine if diversity exists amongst PilA sequences. Methodology. Ninety-four isolates of M. bovoculi collected between 2002 and 2017 from 23 counties throughout California and from five counties in four other Western states were evaluated. Results. DNA sequencing and determination of deduced amino acid sequences revealed ten (designated groups A through J) unique PilA sequences that were ~96.1–99.3 % identical. Pilin groups A and C matched previously reported putative PilA sequences from M. bovoculi isolated from IBK-affected cattle in the USA (Virginia, Nebraska, and Kansas) and Asia (Kazakhstan). The ten pilin sequences identified were only ~74–76 % identical to deduced amino acid sequences of putative pilin proteins identified from the previously reported whole-genome sequences of M. bovoculi derived from deep nasopharyngeal swabs of IBK-asymptomatic cattle. Conclusions. Compared to the diversity reported between structural pilin proteins amongst different serogroups of M. bovis , M. bovoculi PilA from geographically diverse isolates derived from IBK-affected cattle are more conserved.

Despite cancer being the leading cause of death across most racial/ethnic groups, Hispanic women have the second highest mortality rate attributed to diabetes (4.7%) according to the Centers for Disease Control and Prevention (CDC). While cancer and diabetes are two distinct diseases, previous studies have demonstrated that diabetic women have a poor chance of breast cancer survival when compared to nondiabetic women. Well-known key drivers of hyperinsulinemia and insulin resistance, such as insulin and AMPK, are also those involved in breast cancer. This link could possibly contribute to the increased mitogenic effects and risk for aggressive breast cancers in Hispanic women. Based on these findings, metformin, a drug standardly used to treat and prevent hyperglycemia, may be a possible alternative (other than tamoxifen) for breast cancer prevention. Eat, Move, Live (EML), a 5-week community-based program, focuses on targeting possible treatments of chronic diseases and risk reduction through attitude and lifestyle modifications. Exercise, nutritional and health awareness classes were implemented to change participants' perspectives regarding chronic diseases and their susceptibility to other morbidities. Questionnaires were given to the participants at baseline and at two follow-ups (5 weeks and 12 weeks) to assess any changes in their attitudes, behaviors, nutrition, lifestyle and beliefs around taking medication for preventative treatments. A total of 56 participants' pretreatment responses were collected via a five-point Likert scale (1-strongly disagree, 5-strongly agree). Demographic data showed that 69% of the respondents were Hispanic women, of whom 46% completed an education level of high school or less. A majority of the responses averaged a “neutral” response to taking medication for management and prevention of diabetes. We infer that their inability to select a stance in their responses may be associated with the lack of knowledge that the community has regarding chronic diseases and risk-prevention methods. Therefore, we anticipate that availability of proper education tools and resources is essential to potentially prevent future morbidities and mortalities. Ultimately, we aim to establish a pilot study that emphasizes the necessity and importance of interventional programs, like EML, to enhance chemoprevention using metformin and improve health outcomes in high-risk breast cancer populations. Citation Format: Mayra Serrano, Angelica Sanchez, Christine Thai, Katty Nerio, Cristal Resto, Marisela Garcia, Tanya A. Chavez, Laura L. Kruper, Veronica C. Jones, Lisa D. Yee, Alan Nuñez, Ellen J. Rippberger, Angela K. Wong, Noé R. Chávez, Karen Herold, Chidimma M.K. Kalu, Jackelyn A. Alva-Ornelas, Jerneja Tomsic, Krista M. Round, Regina Agulto, Margarita Robles, Ombeni M. Idassi, Kendall J. Kennedy, Christopher Sistrunk, Victoria L. Seewaldt. Receptiveness of metformin as a breast cancer prevention drug within the Hispanic community [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr B119.

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