Hubungan Kecerdasan Intelektual Dengan Prestasi Akademik Pada Siswa SMA N 9 Binsus Manado

Kecerdasan intelektual adalah suatu bentuk penafsiran kemampuan kognitif seseorang, yang berasaskan pada kemampuan bertindak dengan menetapkan suatu tujuan, untuk berfikir secara rasional maupun untuk berhubungan dengan lingkungan sekitarnya yang memuaskan. Prestasi akademik adalah hasil USAha siswa dalam proses belajar yang tercantum dalam sebuah laporan akademik . Tujuan penelitian ini adalah untuk mengetahui hubungan kecerdasan intelektual dengan prestasi akademik pada siswa SMA Negeri 9 Binsus Manado. Penelitian ini bersifat survei analitik dengan pendekatan cross sectional, Sampel diambil dengan teknik pengambilan Purposive Sampling yaitu sebanyak 91 sampel. Instrumen yang digunakan dalam penelitian ini adalah lembar observasi. Hasil penelitian menggunakan analisis uji statistik Chi Square dengan tingkat kemaknaan α = 0,05 atau 95%. Hasil uji statistik didapatkan nilai p = 0,693 > α = 0,05. Kesimpulan dari penelitian ini yaitu tidak ada hubungan hubungan kecerdasan intelektual dengan prestasi akademik pada siswa SMA Negeri 9 Binsus Manado. Saran dilakukan penelitian secara komprehensif dengan jumlah sampel yang lebih banyak dan variabel prestasi akademik yang lain

G Protein Subunit Dissociation and Translocation Regulate Cellular Response to Receptor Stimulation

We examined the role of G proteins in modulating the response of living cells to receptor activation. The response of an effector, phospholipase C-β to M3 muscarinic receptor activation was measured using sensors that detect the generation of inositol triphosphate or diacylglycerol. The recently discovered translocation of Gβγ from plasma membrane to endomembranes on receptor activation attenuated this response. A FRET based G protein sensor suggested that in contrast to translocating Gβγ, non-translocating Gβγ subunits do not dissociate from the αq subunit on receptor activation leading to prolonged retention of the heterotrimer state and an accentuated response. M3 receptors with tethered αq induced differential responses to receptor activation in cells with or without an endogenous translocation capable γ subunit. G protein heterotrimer dissociation and βγ translocation are thus unanticipated modulators of the intensity of a cell's response to an extracellular signal

Compartmentalization of the GABAB receptor signaling complex is required for presynaptic inhibition at hippocampal synapses

Presynaptic inhibition via G-protein-coupled receptors (GPCRs) and voltage-gated Ca(2+) channels constitutes a widespread regulatory mechanism of synaptic strength. Yet, the mechanism of intermolecular coupling underlying GPCR-mediated signaling at central synapses remains unresolved. Using FRET spectroscopy, we provide evidence for formation of spatially restricted (>100 ?) complexes between GABA(B) receptors composed of GB(1a)/GB(2) subunits, G?(o)?(1)?(2) G-protein heterotrimer, and Ca(V)2.2 channels in hippocampal boutons. GABA release was not required for the assembly but for structural reorganization of the precoupled complex. Unexpectedly, GB(1a) deletion disrupted intermolecular associations within the complex. The GB(1a) proximal C-terminal domain was essential for association of the receptor, Ca(V)2.2 and G??, but was dispensable for agonist-induced receptor activation and cAMP inhibition. Functionally, boutons lacking this complex-formation domain displayed impaired presynaptic inhibition of Ca(2+) transients and synaptic vesicle release. Thus, compartmentalization of the GABA(B1a) receptor, G??, and Ca(V)2.2 channel in a signaling complex is required for presynaptic inhibition at hippocampal synapses

Tunable microsecond dynamics of an allosteric switch regulate the activity of a AAA+ disaggregation machine.

Large protein machines are tightly regulated through allosteric communication channels. Here we demonstrate the involvement of ultrafast conformational dynamics in allosteric regulation of ClpB, a hexameric AAA+ machine that rescues aggregated proteins. Each subunit of ClpB contains a unique coiled-coil structure, the middle domain (M domain), proposed as a control element that binds the co-chaperone DnaK. Using single-molecule FRET spectroscopy, we probe the M domain during the chaperone cycle and find it to jump on the microsecond time scale between two states, whose structures are determined. The M-domain jumps are much faster than the overall activity of ClpB, making it an effectively continuous, tunable switch. Indeed, a series of allosteric interactions are found to modulate the dynamics, including binding of nucleotides, DnaK and protein substrates. This mode of dynamic control enables fast cellular adaptation and may be a general mechanism for the regulation of cellular machineries