LAPORAN INDIVIDU PRAKTIK LAPANGAN TERBIMBING (PLT)

Universitas Negeri Yogyakarta (UNY) merupakan perguruan tinggi negeri berbasis pendidikan yang mempunyai tu gas untuk menyelenggarakan pendidikan dan pengabdian kepada masyarakat serta membinatenaga kependidikan. Untuk mewujudkan hal tersebut, maka UNY memberikan pengetahuan dan keterampilan kepada mahasiswa program studi pendidikan pada salah satu matakuliah yaitu Praktik LapanganTerbimbing (PLT). Praktik Lapangan Terbimbing (PLT) merupakan kesempatan bagi mahasiswa untuk mengaplikasi ilmu yang telah dipelajari di bangku perkuliahan serta menjadikan mahasiswa untuk mendapatkan pengalaman nyata dan langsung dalam pemberian ilmu Pendidikan Ilmu Pengetahuan Sosial (PIPS). Praktek Lapangan Terbimbing (PLT) dilaksanakan di SMP Negeri 3 Pakem yang beralamat di Pojok, Harjobinangun, Pakem, Sleman dimulai pada tanggal 15 September 2017 dan diakhiri pada tanggal 15 November 2017. Praktik Lapangan Terbimbing (PLT) merupakan kegiatan pembelajaran di sekolah. Pelaksanaan PLT ini dilakukan dengan mengajar di kelas selama kegiatan pembelajaran di sekolah tersebut sesuai jadwal yang sudahditentukan. Dengan adanya kegiatan PLT ini dapat dijadikan sebagai sarana untuk menjadikan diri sebagai guru atau pendidik yang professional yaitu guru yang mempunyai nilai, sikap, kemampuan dan ketrampilan yang memadai sesuai dengan bidangnya masing-masing

The glycolytic enzyme phosphofructokinase-1 assembles into filaments.

Despite abundant knowledge of the regulation and biochemistry of glycolytic enzymes, we have limited understanding on how they are spatially organized in the cell. Emerging evidence indicates that nonglycolytic metabolic enzymes regulating diverse pathways can assemble into polymers. We now show tetramer- and substrate-dependent filament assembly by phosphofructokinase-1 (PFK1), which is considered the "gatekeeper" of glycolysis because it catalyzes the step committing glucose to breakdown. Recombinant liver PFK1 (PFKL) isoform, but not platelet PFK1 (PFKP) or muscle PFK1 (PFKM) isoforms, assembles into filaments. Negative-stain electron micrographs reveal that filaments are apolar and made of stacked tetramers oriented with exposed catalytic sites positioned along the edge of the polymer. Electron micrographs and biochemical data with a PFKL/PFKP chimera indicate that the PFKL regulatory domain mediates filament assembly. Quantified live-cell imaging shows dynamic properties of localized PFKL puncta that are enriched at the plasma membrane. These findings reveal a new behavior of a key glycolytic enzyme with insights on spatial organization and isoform-specific glucose metabolism in cells

Subtype-specific conformational landscape of NMDA receptor gating.

N-methyl-D-aspartate receptors are ionotropic glutamate receptors that mediate synaptic transmission and plasticity. Variable GluN2 subunits in diheterotetrameric receptors with identical GluN1 subunits set very different functional properties. To understand this diversity, we use single-molecule fluorescence resonance energy transfer (smFRET) to measure the conformations of the ligand binding domain and modulatory amino-terminal domain of the common GluN1 subunit in receptors with different GluN2 subunits. Our results demonstrate a strong influence of the GluN2 subunits on GluN1 rearrangements, both in non-agonized and partially agonized activation intermediates, which have been elusive to structural analysis, and in the fully liganded state. Chimeric analysis reveals structural determinants that contribute to these subtype differences. Our study provides a framework for understanding the conformational landscape that supports highly divergent levels of activity, desensitization, and agonist potency in receptors with different GluN2s and could open avenues for the development of subtype-specific modulators

Stepwise activation of a metabotropic glutamate receptor.

Metabotropic glutamate receptors belong to a family of G protein-coupled receptors that are obligate dimers and possess a large extracellular ligand-binding domain that is linked via a cysteine-rich domain to their 7-transmembrane domain1. Upon activation, these receptors undergo a large conformational change to transmit the ligand binding signal from the extracellular ligand-binding domain to the G protein-coupling 7-transmembrane domain2. In this manuscript, we propose a model for a sequential, multistep activation mechanism of metabotropic glutamate receptor subtype 5. We present a series of structures in lipid nanodiscs, from inactive to fully active, including agonist-bound intermediate states. Further, using bulk and single-molecule fluorescence imaging, we reveal distinct receptor conformations upon allosteric modulator and G protein binding

Structure and dynamics determine G protein coupling specificity at a class A GPCR

G protein-coupled receptors (GPCRs) exhibit varying degrees of selectivity for different G protein isoforms. Despite the abundant structures of GPCR-G protein complexes, little is known about the mechanism of G protein coupling specificity. The beta 2-adrenergic receptor is an example of GPCR with high selectivity for G alpha s, the stimulatory G protein for adenylyl cyclase, and much weaker for the G alpha i family of G proteins inhibiting adenylyl cyclase. By developing a G alpha i-biased agonist (LM189), we provide structural and biophysical evidence supporting that distinct conformations at ICL2 and TM6 are required for coupling of the different G protein subtypes G alpha s and G alpha i. These results deepen our understanding of G protein specificity and bias and can accelerate the design of ligands that select for preferred signaling pathways