ABSTRACT
Smk1 is a meiosis-specific MAP kinase (MAPK) in budding yeast that is required for spore formation. It is localized to prospore membranes (PSMs), the structures that engulf haploid cells during meiosis II (MII). Similar to canonically activated MAPKs, Smk1 is controlled by phosphorylation of its activation-loop threonine (T) and tyrosine (Y). However, activation loop phosphorylation occurs via a noncanonical two-step mechanism in which 1) the cyclin-dependent kinase activating kinase Cak1 phosphorylaytes T207 during MI, and 2) Smk1 autophosphorylates Y209 as MII draws to a close. Autophosphorylation of Y209 and catalytic activity for substrates require Ssp2, a meiosis-specific protein that is translationally repressed until anaphase of MII. Ama1 is a meiosis-specific targeting subunit of the anaphase-promoting complex/cyclosome that regulates multiple steps in meiotic development, including exit from MII. Here, we show that Ama1 activates autophosphorylation of Smk1 on Y209 by promoting formation of the Ssp2/Smk1 complex at PSMs. These findings link meiotic exit to Smk1 activation and spore wall assembly.
Subject(s)
Meiosis , Saccharomyces cerevisiae Proteins/metabolism , Saccharomyces cerevisiae/cytology , Saccharomyces cerevisiae/metabolism , Cdc20 Proteins/metabolism , Cell Membrane/metabolism , Enzyme Stability , Mitogen-Activated Protein Kinases/metabolism , Models, Biological , Mutation/genetics , Phosphorylation , Phosphotyrosine/metabolism , Protein Binding , Spores, Fungal/metabolismABSTRACT
BACKGROUND: The aim of this study was to determine the prevalence of complementary and alternative medicine (CAM) use among patients presenting to a head and neck oncology clinic prior to a diagnosis. METHODS: The study was conducted by administering questionnaires to 102 patients after being seen in the Head and Neck Oncology clinic for their initial consultation. The questionnaire assessed the extent of CAM use, types of CAMs used, and their reasons for use. RESULTS: A total of 132 CAMs were currently being used among 56 patients. The most common CAMs in use were multivitamins (26/132) and vitamin D (21/132). Meditation and yoga were associated with the greatest perceived benefit. The majority of patients obtained their information from family and friends. Most patients were using CAMs for physical health and well-being. CONCLUSION: As CAM use among the population is widespread, it is important for clinicians to specifically address their use on initial presentation.
