Once an activated signaling pathway has elicited the proper changes in target gene expression, the pathway must be inactivated. Otherwise, pathological consequences may result, as exemplified by persistent growth factor initiated signaling in many cancers. Many signaling pathways possess intrinsic negative feedback by which a downstream event in a pathway turns off an upstream event. Describe the negative feedback that down-regulates signals induced by (a) erythropoietin and (b) TGF-β.

Q: Which of the following signaling pathways use conventional molecular activation cascades (signaling…

A: Signaling pathways are a series of chemical reactions within a cell that occur in response to a…

Q: Phorbol esters have been observed to induce the transcription of AP-1–influenced genes. Explain how…

A: Signal transduction is a process in which signals from the extracellular level enter the…

Q: Explain, why many cancer cells maintain high concentrations of insulin-like growth factors (IGFs) in…

A: Cancer is basically the uncontrolled growth and division of cells without the death of the cells in…

Q: Epidermal growth factor (EGF) signals through a receptor, tyrosine kinase. EGF signaling promotes…

A: An epidermal growth factor is a protein-coding gene which is responsible for controlling the…

Q: Cancers are often caused by overactive growth factor receptor signaling (remember growth factor…

A: Cancer is a disease which is caused by the uncontrolled growth of the cells, without regulation of…

Q: Receptor tyrosine kinases (RTKS) .. O a) often mediate pathways involving cell growth and…

A: RTKs are the membrane-bound receptors present in the cells. The role of RTK is phosphorylating the…

Q: In a patient with Essential thrombocytemia, a mutation in JAK2 - a downstream effector of cytokine…

A: Thrombocytemia is an abnormal condition in which number of platelets starts increase Platelets play…

Q: a. A typical cellular response of a mammary epithelial cell to EGF signal is proliferation. the Kd…

A: Proliferation is the cellular response.

Q: Tumor necrosis factor alpha (TNF-α) is an important cytokine used by immune cells to initiate and…

A: We are given a receptor ligand interaction as shown below.T + R  C'T' is the ligand (TNF-), 'R' is…

Q: Cancer-promoting mutations are likely to have different effects on the activity of proteins encoded…

A: Cancer is the unnatural and excessive proliferation of cells that becomes harmful to normal body…

Q: A certain group of Brec-MUT cells expresses low levels of protein A, unlike the high expression…

A: The Brec signaling pathway plays a crucial role in the expression of protein A and the growth of…

Q: BCL2 binds to and inactivates BAX and other pro-apoptotic proteins, thereby inhibiting apoptosis.…

A: Chronic lymphocytic leukaemia is a malignancy in which the bone marrow produces an excessive number…

Q: Describe the mechanisms that limit signaling by the phosphoinositide pathway.

A: Proteins with lipid recognition, kinase, phosphatase, and phospholipase activities are dynamically…

Q: a) What purpose does this forward reaction serve in that pathway?  b) Does the reverse reaction…

A: The Hippo signaling pathway is an evolutionarily conserved signaling pathway that is the latest…

Q: Use the SGF-signaling pathway image as a reference, to answer the following questions. Use the data…

A: ANSWER;-

Q: The ras protein is a mutated G protein that lacks GTPase activity. How does the absence of this…

A: G protein is a membrane protein whose target is a membrane associated adenylyl cyclase enzyme. when…

Q: Aberrant signaling through the EGF receptor signal transduction pathway drives many forms of breast…

A: Cell signaling is mediated by a ligand (usually a hormone but could be other molecules too) binding…

Q: Describe the functions of various components of intracellular signaling pathways with diagrams.…

A: The cell signaling is the process of cell communication within the body. It is the ability of cells…

Q: TSC acts as a tumor suppressor by continually suppressing mTOR and must be inhibited in order for…

A: TSC (Tuberous Sclerosis Complex) acts as a negative regulator of the mTOR (mechanistic target of…

Q: Signaling by tyrosine kinase receptors is generally associated with all of the following except: OA)…

A: A hormone is a class of signaling molecules in multicellular organisms that are sent to distant…

Q: TLRs activate NFkB, AP-1, and IRF transcription factors to induce the expression of inflammatory…

A: The activation of transcription factor such as NFkB, AP-1, and IRF is a complex mechanism involving…

Q: Describe the relationship between Insulin Growth Factor (IGF) and aging.  What role does IGF play in…

A: Insulin Growth Factor IGF is also called somatomedin C. It is structurally similar to the hormone…

Q: First, you apply a signaling ligand known to activate this Gs protein and track yellow fluorescence.…

A: G protein coupled receptors are the cell surface receptors and transmit signals to their…

Q: G protein coupled receptors play an important role in signal transduction in many cells. Label the…

A: Cells in our body interact with each other through chemical molecules. Usually hormones, growth…

Q: Consider the following simplified diagram of a signal transduction pathway that regulates…

A: Apoptosis, or programmed cell death, is a tightly controlled process that is essential for the…

Q: Consider the mTOR pathway described below. Which of the following would be an example of negative…

A: The mTOR (mammalian target of rapamycin) signaling pathway is a critical cellular pathway that…

Q: Mechanistic target of rapamycin (mTOR) is a protein kinase that is a central regulator of cell…

A: The pathway that is described involves a series of events that ultimately lead to mTOR activation.…

Q: Basal cell carcinoma arises from inappropriate activation of the Hedgehog pathway. Which of the…

A: Basal cell carcinoma is a type of skin cancer. Basal cell carcinoma begins in the basal cells is a…

Q: Most mammalian cells have a single immobile cilium called the primary cilium, in which…

A: Intraflagellar transport (IFT) is the process by which proteins are transported into cilia. It…

Q: Aberrant signaling through the Ras-BRaf-MAPK signal transduction pathway drives many cancers. This…

A: Ras-BRaf-MAPK signal transduction pathway is well characterized pathway and known to transduce…

Q: Practice ques tion 1A Mutations in the signalling pathways depicted above have been associated with…

A: For cancer to be triggered in any higher organism generally and mammals specifically, the need is to…

Q: Briefly describe how inflammation can contribute to carcinogenesis and disease progression through…

A: Tumors are heterotypic collections of many cell types including cancer stem cells, progeny tumor…

Q: The activity provides you with a version of the NGF pathway, an example of a RTK. All of the…

A: The given diagram showing Ras - MAP kinase pathway :-

Q: GTP is an important high-energy molecule that facilitates the activation of many cellular sig- nal…

A: GTP (guanosine triphosphate) is an important energy-carrying molecule used in a variety of metabolic…

Q: Atherosclerosis can obstruct or block flow in arteries, including those that provide oxygenated…

A: Artherosclerosis is a cardiovascular disorder caused due to build up of fat deposits in the walls of…

Q: To understand how a signaling pathway works, it is often useful to isolate the cell-surface receptor…

A: In recent years, affinity chromatography, a liquid chromatographic technique for separation and…

Q: Individuals with the hereditary disorder ataxia telangiectasia suffer from neurodegeneration,…

A: Ataxia-telangiectasia is a genetic disorder caused by a point mutation in the ATM gene.

Q: Explain the basics of a disease involving a breakdown in the structure/function of a receptor and/or…

A: Signals molecules are chemically heterogenous compounds and secreted by signaling cells. There are…

Q: The egfr kinase independent transactivation of the ras pathway does require egfr. Explain this…

A: EGFR is a cell surface receptor that binds to certain growth factors and sends signals to the cell's…

Q: Autophagy is an evolutionary conserved catabolic process devoted to the degradation of intracellular…

A: Introduction :  Autophagy is the natural process of  break down and destroying old , damaged cells…

Cell Signaling

It allows cells to perform various cellular activities, coordinate, and interact with other cells. All cells of an organism receive signals from their environments and respond accordingly. Even the unicellular eukaryotes receive signals secreted by other cells and respond. In the case of yeast, mating takes place by signaling between the yeast cells. Communication by cell signaling in a multicellular organism has become a vast and important part of various fields of biology.