Week 1 Flashcards
What are cell surface receptors?
Receptors that are embedded in the plasma membrane of cells.
What are the general features of cell signalling?
There are four basic categories of chemical signaling found in multicellular organisms: paracrine signaling, autocrine signaling, endocrine signaling, and signaling by direct contact. The main difference between the different categories of signaling is the distance that the signal travels through the organism to reach the target cell.
What are the four main signalling messages delivered?
- Survive
- Divide
- Differentiate
- Die
What are the three main diverse responses to cell signalling?
- Decreased rate of firing
- Secretion
- Contraction
What does the signal transduction pathway involve?
The binding of extracellular signaling molecules and ligands to receptors located on the cell surface or inside the cell that trigger events inside the cell, to invoke a response.
What are the four distinct molecular mechanisms for transmembrane signalling?
I: Ligand-gated ion channels.
II: Receptors which possess intrinsic guanylyl cyclase activity.
III: Receptors with intrinsic tyrosine kinase activity.
IV: G protein—coupled receptors
What are the two major classes of cell receptors?
Intracellular receptors, which are found inside of the cell (in the cytoplasm or nucleus), and cell surface receptors, which are found in the plasma membrane.
What are the two main types of ligands in cell signalling?
Ligands that bind to receptors inside the cell, called intracellular ligands, and ligands that bind to receptors outside the cell, called extracellular ligands.
What are the major families of cell surface receptors?
G protein-coupled receptors (GPCRs), enzyme-coupled receptors, and ion channels.
What is the process intracellular signal transduction?
A chain of reactions transmitting signals from the cell surface to a variety of intracellular targets
What are enzyme-coupled receptors?
The receptors for many growth factors, cytokines and hormones and have a major role in regulation of cell growth, proliferation and differentiation.
What are receptor tyrosine kinases?
A group of membrane-bound receptors that play an important role in the normal function of cells.
What are GTP binding proteins?
Transmitting signals outside the cell which cause changes within the cell. They act as molecular switches which are on when binding GTP and off when binding GDP. GTP-binding proteins belong to two families: heterotrimeric G proteins see Transducin and small GTPases
What is the function of G protein-coupled receptors?
Forming a large group of evolutionarily-related proteins that are cell surface receptors that detect molecules outside the cell and activate cellular responses.
What is the most important family of the intracellular receptors?
The nuclear receptors (also known as ‘nuclear hormone receptors’), which includes receptors for steroid hormones, thyroid hormones, retinoids and vitamin D
What is a key characteristic of intracellular nuclear receptors?
Such hormones are lipophilic to facilitate their movement across the cell membrane.
What are the ligands of intracellular receptors?
Small, hydrophobic (water-hating) molecules, since they must be able to cross the plasma membrane in order to reach their receptors.
How are nuclear receptors activated?
By lipid-soluble signals (e.g., steroid hormones) that cross the plasma membrane.
What is cancer?
A disease caused when cells divide uncontrollably and spread into surrounding tissues.
What are the two RAS signalling pathways prominently associated with cancer?
MAP kinase pathway regulating cell proliferation and the phosphoinositide 3-kinase (PI3K) pathway that regulates cell metabolism and survival
What is the tumour microenvironment?
the environment around a tumor, including the surrounding blood vessels, immune cells, fibroblasts, signaling molecules and the extracellular matrix.
What does metastasis mean?
The spread of cancer cells from the place where they first formed to another part of the body.
What is angiogenesis?
The formation of new blood vessels
What do the hallmarks of cancer constitute?
An organizing principle for rationalizing the complexities of neoplastic disease. They include sustaining proliferative signaling, evading growth suppressors, resisting cell death, enabling replicative immortality, inducing angiogenesis, and activating invasion and metastasis.
What underlies the hallmarks of cancer?
Genome instability, which generates the genetic diversity that expedites their acquisition, and inflammation, which fosters multiple hallmark functions.
What are the two newest emerging hallmarks of cancer?
Energy metabolism and evading immune destruction
