Summary The transcription factor Gcr1 controls expression of over 75% of the genes in actively growing yeast. Yet, despite its widespread effects, regulation of Gcr1 itself remains poorly understood. Here we show that posttranscriptional Gcr1 regulation is nutrient-dependent. Moreover, GCR1 RNA contains a long, highly conserved intron, which allows the cell to generate multiple RNA and protein isoforms whose levels change upon glucose depletion. Intriguingly, an isoform generated by intron retention is exported from the nucleus, and its translation is initiated from a conserved, intronic translation start site. Expression of gene products from both the spliced and unspliced RNAs is essential, as cells expressing only one isoform cannot adjust their metabolic program in response to environmental changes. Finally, we show that the Gcr1 proteins form dimers, providing an elegant mechanism by which this one gene, through its regulation, can perform the repertoire of transcriptional activities necessary for fine-tuned environmental response.

Coccidioidomycosis is a fungal infection endemic to the Southwestern United States which is associated with high morbidity and mortality in immunocompromised hosts. Serology is the main diagnostic tool, although less sensitive among immunocompromised hosts. (1→3)-β-D-glucan (BDG) is a non-specific fungal diagnostic test that may identify suspected coccidioidomycosis and other invasive fungal infections. We retrospectively investigated the utility of BDG between 2017 and 2021 in immunocompromised hosts with positive Coccidioides spp. cultures at our institutions. During the study period, there were 368 patients with positive cultures for Coccidioides spp.; among those, 28 patients were immunocompromised hosts, had both Coccidioides serology and BDG results available, and met other inclusion and exclusion criteria. Half of the patients had positive Coccidioides serology, and 57% had a positive BDG ≥ 80 pg/mL. Twenty-three (82%) had at least one positive test during their hospitalization. Among immunocompromised hosts with suspicion for coccidioidomycosis, the combination of Coccidioides serology and BDG can be useful in the initial work up and the timely administration of appropriate antifungal therapy. However, both tests failed to diagnose many cases, underscoring the need for better diagnostic techniques for identifying coccidioidomycosis in this population.

INTRODUCTION:Coccidioidomycosis, a fungal infection endemic to the Southwest United States, can take on many appearances on chest imaging. A miliary pattern is seen less frequently. In the immunocompromised patient, this can be a quandary for physicians as it may mimic tuberculosis. CASE PRESENTATION:A 34-year-old woman with systemic lupus erythematosus, on immunosuppressive therapy, presented with two months of fevers, fatigue, and 25-pound weight loss. Additional symptoms included dry cough, pleuritic chest pain, and vision changes. Other history was notable for birthplace in a developing country and immigration to Arizona in early childhood. On presentation, a computed tomography of the chest revealed diffuse miliary nodules with confluent necrotizing pneumonia in the left lower lobe. Ophthalmology was consulted for her vision disturbances and found creamy chorioretinal lesions bilaterally on fundoscopic exam. Quantiferon testing was indeterminate. Beta-D glucan was elevated, as were coccidioidomycosis IgM and IgG antibodies. Bronchoscopy with bronchoalveolar lavage was subsequently performed, as the patient was unable to provide satisfactory sputum samples. These cultures were negative for tuberculosis, and the initiation of antitubercular therapy was avoided. Intravenous Amphotericin and oral Fluconazole was initiated during her hospitalization, followed by a prolonged course of Fluconazole at discharge. DISCUSSION: There was concern for disseminated tuberculosis, given the patient's miliary pattern on imaging, chorioretinitis, and history of birth place. As coccidioidomycosis is endemic to Arizona, the patient was empirically started on antifungal treatment, but precautions and workup of active tuberculosis were still taken. Antitubercular therapy was to be held until the appropriate respiratory samples were collected. The patient afforded this delay as she remained hemodynamically stable without oxygen requirements. This decision also minimized the risk of building resistance and subjecting the patient to potentially harmful side effects. Cultures resulted negative for tuberculosis, and the patient's rapid clinical improvement on antifungal therapy supported her diagnosis of pulmonary coccidioidomycosis. She was placed on oral fluconazole and prednisolone eye drops at discharge; her follow up with Infectious Diseases nine months later found the patient to be asymptomatic with near complete resolution of the nodules on chest imaging. CONCLUSIONS:Coccidioidomycosis can have acute to subacute presentations of pneumonia with imaging findings ranging from focal infiltrates and nodular opacities to cavitary lesions. A miliary pattern can also occur, which should prompt a thorough infectious history and consideration for more invasive testing prior to empiric treatment of tuberculosis in a stable patient.

The general model for gene evolution is that new genes are derived from old genes by speciation or duplication. Recently however, a large number of de novo genes have been discovered. YNR034W‐A is a yeast gene that has two alleles. The long sequence is partial de novo protein that is 24 residues longer than the ancestral protein (98 residues) with a different sequence after residue 65. This project aims to understand the effects of the frameshift mutation in the ancestral gene on protein folding of the partial de novo protein. Both alleles were codon‐optimized, sub‐cloned into N‐terminal polyHis‐tagged vectors, and over‐expressed in E. coli. Protein was purified by lysis, nickel affinity chromatography, and dialysis into refolding buffer. Far UV circular dichroism determined secondary structure and thermal melts were used to determine thermal stability. The longer protein is less stable in solution and more aggregation prone due to the C‐terminal tail. Further studies include truncation of the long protein at positions 65 and 98. The data support the hypothesis that de novo proteins are intrinsically disordered; these proteins provide a useful platform for understanding protein folding and evolution.

The University of Arizona UAN Chapter has organized three outreach activities. The Visiting Scholars Program sends undergraduates into high school science classrooms to present research and provide information on opportunities in science. Presenters also serve as mentors by discussing a “well‐rounded” college experience. Furthermore, teachers support the program and are interested in future interactions. Our BlastOff! Summer Camp is a five‐day program that recruits middle school students from underrepresented populations in the sciences. Campers are exposed to “wet lab” techniques, scientific theories, and hands‐on projects; field trips and guest speakers complement lab activities. In the spring, we invite undergraduates and high school students to present their research at our Biology, Engineering, Chemistry Undergraduate Research (BECUR) Conference. For the poster competition, we offer cash prizes and travel awards to the ASBMB meeting. High school students gain experience at this university‐level conference interacting with UA students and faculty. We select two undergraduates to give seminars and invite a Keynote Speaker from the field of biochemistry or molecular biology.