Building Connections to Biology and Community through Service-Learning and Research Experiences.

Service-learning and undergraduate research experiences are high-impact practices that have become more common in the sciences, but the benefits of short-term experiences have not been thoroughly investigated. The purpose of this study was to compare within-semester gains for students in a short-term service-learning (SL) or short-term research project (RP) in terms of students' (i) motivation to learn biology, (ii) scientific literacy, (iii) perception of the relevance of biology to their lives, and (iv) learning gains associated with course learning outcomes. The impacts of brief service-learning and research project experiences were compared using direct and indirect assessments, including qualitative coding of open-ended response questions and quantitative analysis of exams and Likert-type items.

Fostering Inclusion through an Interinstitutional, Community-Engaged, Course-Based Undergraduate Research Experience.

Creation of an inclusive environment requires a culture of equity, justice, value and respect for diverse backgrounds, and opportunities for students to engage with communities while addressing issues in science and society. These tasks are particularly challenging for institutions lacking a diverse population. Here, we demonstrate evidence of a successful model for creating an inclusive environment in an interinstitutional course between a large, public, historically black institution and a small, private, primarily white institution.

Echinomycin protects mice against relapsed acute myeloid leukemia without adverse effect on hematopoietic stem cells.

Acute myeloid leukemia (AML) often relapses following chemotherapy-induced remission and is generally chemo-resistant. Given the potential role for cancer stem cells in relapse, targeting of the leukemia-initiating cell (LIC) in AML may provide improved outcome following remission induction. However, due to overlap in their self-renewal program with normal hematopoietic stem cells (HSCs), therapeutic targeting of the LIC may have an adverse effect on long-term hematopoietic recovery.

Eradicating acute myeloid leukemia in a Mll(PTD/wt):Flt3(ITD/wt) murine model: a path to novel therapeutic approaches for human disease.

The coexpression of the MLL partial tandem duplication (PTD) and the FLT3 internal tandem duplication (ITD) mutations associate with a poor outcome in cytogenetically normal acute myeloid leukemia (AML). In mice, a double knock-in (dKI) of Mll(PTD/wt) and Flt3(ITD/wt) mutations induces spontaneous AML with an increase in DNA methyltransferases (Dnmt1, 3a, and 3b) and global DNA methylation index, thereby recapitulating its human AML counterpart. We determined that a regulator of Dnmts, miR-29b, is downregulated in bone marrow of dKI AML mice.

Mll partial tandem duplication and Flt3 internal tandem duplication in a double knock-in mouse recapitulates features of counterpart human acute myeloid leukemias.

The MLL-partial tandem duplication (PTD) associates with high-risk cytogenetically normal acute myeloid leukemia (AML). Concurrent presence of FLT3-internal tandem duplication (ITD) is observed in 25% of patients with MLL-PTD AML. However, mice expressing either Mll-PTD or Flt3-ITD do not develop AML, suggesting that 2 mutations are necessary for the AML phenotype.

Enhanced T-cell signaling in cells bearing linker for activation of T-cell (LAT) molecules resistant to ubiquitylation.

Linker for activation of T cells (LAT) plays a central role in T-cell activation by nucleating signaling complexes that are critical for the propagation of T-cell signals from the plasma membrane to the cellular interior. The role of phosphorylation and palmitoylation in LAT function has been well studied, but not much is known about other strategies by which the cell modulates LAT activity. We have focused on LAT ubiquitylation and have mapped the sites on which LAT is ubiquitylated.

Formation of STIM and Orai complexes: puncta and distal caps.

In the last few years, great progress has been made in understanding how stromal interacting molecule 1 (STIM1), a protein containing a calcium sensor that is located in the endoplasmic reticulum, and Orai1, a protein that forms a calcium channel in the plasma membrane, interact and give rise to store-operated calcium entry. Pharmacological depletion of calcium stores leads to the formation of clusters containing STIM and Orai that appear to be sites for calcium influx. Similar puncta are also produced in response to physiological stimuli in immune cells.

Rab35 and its GAP EPI64C in T cells regulate receptor recycling and immunological synapse formation.

Upon antigen recognition, T-cell receptor (TCR/CD3) and other signaling molecules become enriched in a specialized contact site between the T cell and antigen-presenting cell, i.e. the immunological synapse (IS).

Dynamic movement of the calcium sensor STIM1 and the calcium channel Orai1 in activated T-cells: puncta and distal caps.

The proteins STIM1 and Orai1 are the long sought components of the store-operated channels required in T-cell activation. However, little is known about the interaction of these proteins in T-cells after engagement of the T-cell receptor. We found that T-cell receptor engagement caused STIM1 and Orai1 to colocalize in puncta near the site of stimulation and accumulate in a dense structure on the opposite side of the T-cell.

T-cell antigen receptor-induced signaling complexes: internalization via a cholesterol-dependent endocytic pathway.

T-cell antigen receptor engagement causes the rapid assembly of signaling complexes. The adapter protein SLP-76, detected as SLP-yellow fluorescent protein, initially clustered with the TCR and other proteins, then translocated medially on microtubules. As shown by total internal reflection fluorescence microscopy and the inhibition of SLP-76 movement at 16 degrees C, this movement required endocytosis.

A small surface hydrophobic stripe in the coiled-coil domain of type I keratins mediates tetramer stability.

Intermediate filaments (IFs) are fibrous polymers encoded by a large family of differentially expressed genes that provide crucial structural support in the cytoplasm and nucleus in higher eukaryotes. The mechanisms involved in bringing together approximately 16 elongated coiled-coil dimers to form an IF are poorly defined. Available evidence suggests that tetramer subunits play a key role during IF assembly and regulation.

Keratin 16 expression defines a subset of epithelial cells during skin morphogenesis and the hair cycle.

The morphogenesis of skin epithelia and adult hair follicle cycling both require integrated signaling between the epithelium and underlying mesenchyme. Because of their unique regulation, keratin intermediate filaments represent useful markers for the analysis of determination and differentiation processes in complex epithelia, such as the skin. In this study, we analyzed the distribution of mouse type I keratin 16 during skin morphogenesis, in the adult hair cycle, and in challenged epidermis.