- There are 4 main types of receptors: ligand-gated ion channels, G-protein coupled receptors, kinase-linked receptors, and nuclear receptors.
- Ligand-gated ion channels directly open ion channels, G-protein receptors signal through G-proteins, kinase receptors signal through phosphorylation, and nuclear receptors regulate gene transcription as transcription factors.
- Receptors recognize a wide range of ligands and allow cells to respond to changes in their internal or external environment through second messenger signaling pathways.
GPCRs are the most dynamic and most abundant all the receptors. The G protein-coupled receptor (GPCR) superfamily comprises the largest and most diverse group of proteins in mammals. GPCRs are responsible for every aspect of human biology from vision, taste, sense of smell, sympathetic and parasympathetic nervous functions, metabolism, and immune regulation to reproduction. GPCRs interact with a number of ligands ranging from photons, ions, amino acids, odorants, pheromones, eicosanoids, neurotransmitters, peptides, proteins, and hormones.
Nevertheless, for the majority of GPCRs, the identity of their natural ligands is still unknown, hence remain orphan receptors.
The simple dogma that underpins much of our current understanding of GPCRs, namely,
one GPCR gene− one GPCR protein− one functional GPCR− one G protein −one response
is showing distinct signs of wear.
Assignment on Secondary messengers and intracellular signalingDeepak Kumar
Assignment on Secondary messengers: cyclic AMP, cyclic GMP, calcium ion, inositol 1,4,5- trisphosphate, (IP3), NO, and diacylglycerol. Detailed study of following intracellular signaling pathways: cyclic AMP signaling pathway, mitogen-activated protein kinase (MAPK) signaling, Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathway.
Definition
Classification and description of each class.
Description of individual receptor.
Forces affecting the drug receptor binding.
Binding of drug receptor affect drug action.
Agonist and antagonist.
Disease due to malfunctioning of receptors.
New drug design based on structure of receptors
Receptor as target for drug discovery.
Drug action not mediated by receptor.
This presentation is about the neurotransmitter 5-HT (serotonin), we focused on its definition, biosynthesis, storage and destruction, with mentioning its both central and peripheral effects, and lastly the serotonin receptors in the human body, as well as their agonist and antagonists.
Assignment on Need of cell signaling, Steps in cell signaling, Intercellular signaling pathways, Types of intercellular signaling pathways, Intracellular signaling pathways, Receptors, Intercellular and intracellular signaling pathways. Classification of receptor family and molecular structure ligand gated ion channels; Gprotein coupled receptors, tyrosine kinase receptors and nuclear receptors.
GPCRs are the most dynamic and most abundant all the receptors. The G protein-coupled receptor (GPCR) superfamily comprises the largest and most diverse group of proteins in mammals. GPCRs are responsible for every aspect of human biology from vision, taste, sense of smell, sympathetic and parasympathetic nervous functions, metabolism, and immune regulation to reproduction. GPCRs interact with a number of ligands ranging from photons, ions, amino acids, odorants, pheromones, eicosanoids, neurotransmitters, peptides, proteins, and hormones.
Nevertheless, for the majority of GPCRs, the identity of their natural ligands is still unknown, hence remain orphan receptors.
The simple dogma that underpins much of our current understanding of GPCRs, namely,
one GPCR gene− one GPCR protein− one functional GPCR− one G protein −one response
is showing distinct signs of wear.
Assignment on Secondary messengers and intracellular signalingDeepak Kumar
Assignment on Secondary messengers: cyclic AMP, cyclic GMP, calcium ion, inositol 1,4,5- trisphosphate, (IP3), NO, and diacylglycerol. Detailed study of following intracellular signaling pathways: cyclic AMP signaling pathway, mitogen-activated protein kinase (MAPK) signaling, Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathway.
Definition
Classification and description of each class.
Description of individual receptor.
Forces affecting the drug receptor binding.
Binding of drug receptor affect drug action.
Agonist and antagonist.
Disease due to malfunctioning of receptors.
New drug design based on structure of receptors
Receptor as target for drug discovery.
Drug action not mediated by receptor.
This presentation is about the neurotransmitter 5-HT (serotonin), we focused on its definition, biosynthesis, storage and destruction, with mentioning its both central and peripheral effects, and lastly the serotonin receptors in the human body, as well as their agonist and antagonists.
Assignment on Need of cell signaling, Steps in cell signaling, Intercellular signaling pathways, Types of intercellular signaling pathways, Intracellular signaling pathways, Receptors, Intercellular and intracellular signaling pathways. Classification of receptor family and molecular structure ligand gated ion channels; Gprotein coupled receptors, tyrosine kinase receptors and nuclear receptors.
The signal transduction pathway uses a network of interactions within cells, among cells, and throughout plant.
The external signals that affect plant growth and development include many aspects of the plant’s physical, chemical, and biological environments. Some external signals come from other plants.
Many signals interact cooperatively and synergistically with each other to produce the final response. Signal combinations that induce such complex plant responses include red and blue light, gravity and light, growth regulators and mineral nutrients .
For example the overall regulation of seed germination involves control by both external factors and internal signals.
Remote Sensing and Computational, Evolutionary, Supercomputing, and Intellige...University of Maribor
Slides from talk:
Aleš Zamuda: Remote Sensing and Computational, Evolutionary, Supercomputing, and Intelligent Systems.
11th International Conference on Electrical, Electronics and Computer Engineering (IcETRAN), Niš, 3-6 June 2024
Inter-Society Networking Panel GRSS/MTT-S/CIS Panel Session: Promoting Connection and Cooperation
https://www.etran.rs/2024/en/home-english/
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
This presentation explores a brief idea about the structural and functional attributes of nucleotides, the structure and function of genetic materials along with the impact of UV rays and pH upon them.
Nutraceutical market, scope and growth: Herbal drug technologyLokesh Patil
As consumer awareness of health and wellness rises, the nutraceutical market—which includes goods like functional meals, drinks, and dietary supplements that provide health advantages beyond basic nutrition—is growing significantly. As healthcare expenses rise, the population ages, and people want natural and preventative health solutions more and more, this industry is increasing quickly. Further driving market expansion are product formulation innovations and the use of cutting-edge technology for customized nutrition. With its worldwide reach, the nutraceutical industry is expected to keep growing and provide significant chances for research and investment in a number of categories, including vitamins, minerals, probiotics, and herbal supplements.
Toxic effects of heavy metals : Lead and Arsenicsanjana502982
Heavy metals are naturally occuring metallic chemical elements that have relatively high density, and are toxic at even low concentrations. All toxic metals are termed as heavy metals irrespective of their atomic mass and density, eg. arsenic, lead, mercury, cadmium, thallium, chromium, etc.
Comparing Evolved Extractive Text Summary Scores of Bidirectional Encoder Rep...University of Maribor
Slides from:
11th International Conference on Electrical, Electronics and Computer Engineering (IcETRAN), Niš, 3-6 June 2024
Track: Artificial Intelligence
https://www.etran.rs/2024/en/home-english/
DERIVATION OF MODIFIED BERNOULLI EQUATION WITH VISCOUS EFFECTS AND TERMINAL V...Wasswaderrick3
In this book, we use conservation of energy techniques on a fluid element to derive the Modified Bernoulli equation of flow with viscous or friction effects. We derive the general equation of flow/ velocity and then from this we derive the Pouiselle flow equation, the transition flow equation and the turbulent flow equation. In the situations where there are no viscous effects , the equation reduces to the Bernoulli equation. From experimental results, we are able to include other terms in the Bernoulli equation. We also look at cases where pressure gradients exist. We use the Modified Bernoulli equation to derive equations of flow rate for pipes of different cross sectional areas connected together. We also extend our techniques of energy conservation to a sphere falling in a viscous medium under the effect of gravity. We demonstrate Stokes equation of terminal velocity and turbulent flow equation. We look at a way of calculating the time taken for a body to fall in a viscous medium. We also look at the general equation of terminal velocity.
Deep Behavioral Phenotyping in Systems Neuroscience for Functional Atlasing a...Ana Luísa Pinho
Functional Magnetic Resonance Imaging (fMRI) provides means to characterize brain activations in response to behavior. However, cognitive neuroscience has been limited to group-level effects referring to the performance of specific tasks. To obtain the functional profile of elementary cognitive mechanisms, the combination of brain responses to many tasks is required. Yet, to date, both structural atlases and parcellation-based activations do not fully account for cognitive function and still present several limitations. Further, they do not adapt overall to individual characteristics. In this talk, I will give an account of deep-behavioral phenotyping strategies, namely data-driven methods in large task-fMRI datasets, to optimize functional brain-data collection and improve inference of effects-of-interest related to mental processes. Key to this approach is the employment of fast multi-functional paradigms rich on features that can be well parametrized and, consequently, facilitate the creation of psycho-physiological constructs to be modelled with imaging data. Particular emphasis will be given to music stimuli when studying high-order cognitive mechanisms, due to their ecological nature and quality to enable complex behavior compounded by discrete entities. I will also discuss how deep-behavioral phenotyping and individualized models applied to neuroimaging data can better account for the subject-specific organization of domain-general cognitive systems in the human brain. Finally, the accumulation of functional brain signatures brings the possibility to clarify relationships among tasks and create a univocal link between brain systems and mental functions through: (1) the development of ontologies proposing an organization of cognitive processes; and (2) brain-network taxonomies describing functional specialization. To this end, tools to improve commensurability in cognitive science are necessary, such as public repositories, ontology-based platforms and automated meta-analysis tools. I will thus discuss some brain-atlasing resources currently under development, and their applicability in cognitive as well as clinical neuroscience.
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
2. RECEPTOR PROTEINS
ISOLATION AND CLONING OF RECEPTORS :
• In the 1970s, pharmacology entered a new phase
when receptors, which had until then been
theoretical entities, began to emerge as
biochemical realities following the development
of receptor-labelling techniques, which made it
possible to extract and purify receptor material.
This approach was first used successfully on the
nicotinic acetylcholine receptor.
3. Ligand-gated ion channels
• These are also known as ionotropic receptors.
These are membrane proteins with a similar
structure to other ion channels, and
incorporate a ligand-binding (receptor) site,
usually in the extracellular domain. Typically,
these are the receptors on which fast
neurotransmitters act. Examples include the
nicotinic acetylcholine receptor; GABAA
receptor; and glutamate receptors of the
NMDA.
4. • Receptors of this type control the fastest
synaptic events in the nervous system, in
which a neurotransmitter acts on the
postsynaptic membrane of a nerve or muscle
cell and transiently increases its permeability
to particular ions.
5. Mechanism
• Most excitatory neurotransmitters, such as
acetylcholine at the neuromuscular junction or
glutamate in the central nervous system, cause
an increase in Na+ and K+s permeability.
• This results in a net inward current carried mainly
by Na+, which depolarises the cell and increases
the probability that it will generate an action
potential. The action of the transmitter reaches a
peak in a fraction of a millisecond, and usually
decays within a few milliseconds.
6. • The sheer speed of this response implies that
the coupling between the receptor and the
ionic channel is a direct one, and the
molecular structure of the receptor-channel
complex agrees with this. In contrast to other
receptor families, no intermediate
biochemical steps are involved in the
transduction process.
7.
8.
9. G-protein-coupled receptors (GPCRs)
• These are also known as metabotropic receptors
or 7-transmembrane-spanning (heptahelical)
receptors.
• They are membrane receptors that are coupled to
intracellular effector systems via a G-protein.
They constitute the largest family, and include
receptors for many hormones and slow
transmitters, for example the muscarinic
acetylcholine receptor, adrenergic receptors and
chemokine receptors.
10. • Many neurotransmitters, apart from peptides,
can interact with both GPCRs and with ligand-
gated channels, allowing the same molecule
to produce a wide variety of effects. Individual
peptide hormones, on the other hand,
generally act either on GPCRs or on kinase-
linked receptors, but rarely on both. The first
GPCR to be fully characterised was the β-
adrenoceptor, which was cloned in 1986.
11. Main G-protein subtypes
Gαs (stimulatory)
• Many amine and other receptors (e.g.
catecholamines, histamine, serotonin)
• They stimulate adenylyl cyclase, causing
increased cAMP formation.
• There are many examples of such receptors,
including adrenoceptors, glucagon receptors,
thyrotropin receptors, and certain subtypes of
dopamine and serotonin receptors
12. Gαi (inhibitory)
These include opioid, cannabinoid receptors .
Inhibits adenylyl cyclase, decreasing cAMP
formation.
Gαq
• These include amine, peptide and prostanoid
receptors. They activate phospholipase C,
increasing production of second messengers
inositol trisphosphate and diacylglycerol
13. Gβγ
• These subunits include all GPCRs As for Gα
subunits, also:
• activate potassium channels
• inhibit voltage-gated calcium channels
• activate GPCR kinases
• activate mitogen-activated protein kinase
cascade.
14. Mechanism
• G-proteins consist of three subunits: α, β and
γ. Guanine nucleotides bind to the α subunit,
which has enzymic activity, catalysing the
conversion of GTP to GDP. The β and γ
subunits remain together as a βγ complex.
• In the 'resting' state, the G-protein exists as an
unattached αβγ trimer, with GDP occupying
the site on the α subunit.
15. • When a GPCR is activated by an agonist molecule,
a conformational change occurs, involving the
cytoplasmic domain of the receptor, causing it to
acquire high affinity for αβγ. Association of αβγ
with the receptor causes the bound GDP to
dissociate and to be replaced with GTP (GDP-GTP
exchange), which in turn causes dissociation of
the G-protein trimer, releasing α-GTP and βγ
subunits; these are the 'active' forms of the G-
protein, which diffuse in the membrane and can
associate with various enzymes and ion channels,
causing activation of the target
16. • Signalling is terminated when the hydrolysis of
GTP to GDP occurs through the GTPase activity of
the α subunit. The resulting α-GDP then
dissociates from the effector, and reunites with
βγ, completing the cycle.
• GTP hydrolysis is the step that terminates the
ability of the α subunit to produce its effect,
regulation of its GTPase activity by the effector
protein means that the activation of the effector
tends to be self-limiting.
17. Phosphorylation: A Common Theme
• Almost all second messenger signaling involves
reversible phosphorylation, which performs two
principal functions in signaling: amplification and
flexible regulation.
• In amplification, rather like GTP bound to a G protein,
the attachment of a phosphoryl group to a serine,
threonine, or tyrosine residue powerfully amplifies the
initial regulatory signal by recording a molecular
memory that the pathway has been activated;
dephosphorylation erases the memory, taking a longer
time to do so than is required for dissociation of an
allosteric ligand.
18. • In flexible regulation, the difference in the
substrate specificities is regulated by second
messengers and this is responsible for the
signaling pathways that may be independently
regulated. In this way, cAMP, Ca2+, or other
second messengers can use the presence or
absence of particular kinases or kinase substrates
to produce quite different effects in different cell
types. Inhibitors of protein kinases have great
potential as therapeutic agents, particularly in
neoplastic diseases.
19. TARGETS FOR G-PROTEINS
• The main targets for G-proteins, through which GPCRs
control different aspects of cell function are:
• adenylyl cyclase, the enzyme responsible for cAMP
formation
– adenylate cyclase catalyses formation of the intracellular
messenger cAMP
– cAMP activates various protein kinases that control cell
function in many different ways by causing
phosphorylation of various enzymes, carriers and other
proteins.
20. • phospholipase C, the enzyme responsible for inositol
phosphate and diacylglycerol (DAG) formation
– catalyses the formation of two intracellular messengers,
IP3 and DAG, from membrane phospholipid
– IP3 acts to increase free cytosolic Ca2+ by releasing Ca2+
from intracellular compartments
– increased free Ca2+ initiates many events, including
contraction, secretion, enzyme activation and membrane
hyperpolarisation
– DAG activates protein kinase C, which controls many
cellular functions by phosphorylating a variety of proteins.
21. • ion channels, (e.g. potassium and calcium
channels, thus affecting membrane
excitability, transmitter release and
contractility)
• Rho A/Rho kinase, a system that controls the
activity of many signalling pathways
controlling cell growth and proliferation,
smooth muscle contraction, etc.
22. Kinase-linked and related receptors
• This is a large and heterogeneous group of membrane
receptors responding mainly to protein mediators.
They comprise an extracellular ligand-binding domain
linked to an intracellular domain by a single
transmembrane helix. In many cases, the intracellular
domain is enzymic in nature (with protein kinase or
guanylyl cyclase activity).
• The receptors all share a common architecture, with a
large extracellular ligand-binding domain connected via
a single membrane-spanning helix to the intracellular
domain.
23. • Cytokine receptors have an intracellular domain
that binds and activates cytosolic kinases when
the receptor is occupied.
• These receptors include those for insulin and for
various cytokines and growth factors; the
receptor for atrial natriuretic factor is the main
example of the guanylyl cyclase type. The two
kinds are very similar structurally, even though
their transduction mechanisms differ
24. • They are involved mainly in events controlling cell
growth and differentiation, and act indirectly by
regulating gene transcription.
• Two important pathways are:
– the Ras/Raf/mitogen-activated protein (MAP) kinase
pathway, which is important in cell division, growth and
differentiation
– the Jak/Stat pathway activated by many cytokines, which
controls the synthesis and release of many inflammatory
mediators.
• A few hormone receptors (e.g. atrial natriuretic factor)
have a similar architecture and are linked to guanylate
cyclase.
25.
26. Nuclear receptors
• The fourth type of receptors we will consider
belong to the nuclear receptor family. These are
receptors that regulate gene transcription.
• The term nuclear receptors is something of a
misnomer, because some are actually located in
the cytosol and migrate to the nuclear
compartment when a ligand is present. They
include receptors for steroid hormones, thyroid
hormone, and other agents such as retinoic acid
and vitamin D.
27. • By the 1980s, it was clear that receptors for
steroid hormones such as oestrogen and the
glucocorticoids were present in the cytoplasm
of cells and translocated into the nucleus after
binding with their steroid partner. Other
hormones, such as the thyroid hormone T3
and the fat-soluble vitamins D and A (retinoic
acid) and their derivatives that regulate
growth and development
28. • Two main categories:
– those that are present in the cytoplasm, form
homodimers in the presence of their partner, and
migrate to the nucleus. Their ligands are mainly
endocrine in nature (e.g. steroid hormones).
– those that are generally constitutively present in the
nucleus and form heterodimers with the retinoid X
receptor. Their ligands are usually lipids (e.g. the fatty
acids).
– A third subgroup transduce mainly endocrine signals
but function as heterodimers with retinoid X receptor
(e.g. the thyroid hormone).
29. • The receptor family is responsible for the
pharmacology of approximately 10%, and the
pharmacokinetics of some 60%, of all
prescription drugs.
30. Idiosyncracy
• Individuals may vary considerably in their
response to a drug; indeed, a single individual
may respond differently to the same drug at
different times during the course of treatment.
Occasionally, individuals exhibit an unusual or
idiosyncratic drug response, one that is
infrequently observed in most patients. The
idiosyncratic responses are usually caused by
genetic differences in metabolism of the drug or
by immunologic mechanisms, including allergic
reactions.
31. Hypersensitivity
• The term hypersensitivity usually refers to
allergic or other immunologic responses to
drugs.
• Hypersensitivity can be classified as antibody-
mediated or cell-mediated. Three types of
hypersensitivity are antibody-mediated (types
I–III), while the fourth is cell-mediated (type
IV).
32. • Hypersensitivity occurs in two phases: the
sensitization phase and the effector phase.
Sensitization occurs upon initial encounter
with an antigen; the effector phase involves
immunologic memory and results in tissue
pathology upon a subsequent encounter with
that antigen.