Tag for questions related to the process of cells receiving a stimulus from its environment, or from itself (autocrine signaling), and responding as a result of the stimulus.

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Post-translation modifications of proteins that are regulated in breast cancer [closed]

I have a set of proteins which are up regulated in breast cancer. I was asked to find post-translational modifications (PTMs) for them, which I found based on databases but my question is that, what ...
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1answer
61 views

Why RTK Truncations So Common in Transformations

So if we can understand that RTKs are 'floating' around the surface of a cell as monomers until ligand binds one of the monomers and thereby acts as a bridge to facilitate binding to a corresponding ...
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1answer
28 views

Can a protein kinase phosphorylate both a threonine and tyrosine residue?

I know that some kinases can phosporylate both serine and threonine residues because of their structural similarities, but can such a kinase phosphorylate a tyrosine residue as well? If not, then why?...
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24 views

Insulin and leptin action on Anorexigenic Neurons in Hypothalamus?

Receptors for Insulin are present on liver, adipose tissue and muscles BUT also Insulin Receptors are present in arcuate nucleus of hypothalamus where it influences anorexogenic neurons through IRS2 ...
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1answer
37 views

Why are both glucagon and cortisol released in hypoglycemia?

Cortisol is released in response to prolonged stresses; one situation when cortisol is released is when blood glucose level is low. In this situation cortisol acts on adipose tissue promoting fatty ...
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1answer
67 views

Cell biology books

I'd like to know, what is the best list of books for non-biologist to understand, how signalling between organels is organized inside of eukaryotic cells. I really want to get how cell as separate ...
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1answer
33 views

What information do bipolar cells encode?

Short version: I don't see what information on-centre bipolar cells are actually capturing. Longer: Actually, the question could be extended to on-centre retinal cells as well, but I'll focus on ...
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1answer
17 views

How is receptor production (recycling) regulated?

My understanding of receptor downregulation is that when activated, a receptor then gets absorbed into its cell, as shown in this weird video. It then gets either recycled or degraded. Tolerance ...
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0answers
8 views

Is EGF-mediated proliferation symmetric?

It's known that the MAPK signaling cascade (say, ERK) is downstream of EGFR in epithelial cells, and that EGFR activation can cause proliferation in some cell types in some situations. My question is ...
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1answer
32 views

Advantage of GCPRs over RTKs or other receptor protein kinases

My book lists two important differences between GCPRs and receptor protein kinases: GCPRs do not directly activate a signal transduction pathway. It only does so indirectly, via a G protein. On the ...
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1answer
133 views

If so many different hormones/molecules work by activating adenylyl cyclase, how do they have different effects?

It seems that many hormones and molecules work by activating adenylyl cyclase to convert $\text{ATP}$ to $\text{cAMP}$, such as adrenaline and glucagon. Both of these seem to bind to $\text G$ protein ...
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0answers
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Arginine finger for regulating GTPase activity of heterotrimeric G-proteins as well?

I've seen video on iBiology discussing mechanism of Ras-Gap protein regulation of Ras protein (monomeric G-protein) involving an "arginine finger' from Ras-Gap for stabilization of intermediate in ...
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0answers
31 views

What's the purpose of Cdk activity having more than one method of becoming inactive?

Cdk becomes partially active once its bound to cyclin and then gets phosphorylated and fully active once a Cdk-activating kinase (CAK) phosphorylates the partially active Cdk. This fully activated Cdk ...
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1answer
22 views

To have a drug travel to a specific place in the body can you just coat the drug in extracellular signals recognized by target cells?

In a lecture of mine the professor was talking about the issue faced in regards to drug therapy when it comes to targeting lung cells in cystic fibrosis. It was said that if unless the drug gets ...
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0answers
78 views

What is the essence of difference of how different chemicals affect the same receptor?

It is known that various chemicals can bind to the same receptor type, producing different effects. Be these chemicals agonists or antagonists, there are more variations in how they influence the ...
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1answer
244 views

What is a mechanical cue?

I was attending a talk related to neurogenesis. So one professor was asking a question related to biochemical cues and mechanical cues (related to signaling pathways I believe). Cue as far as I ...
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0answers
26 views

What is the lifetime of the vasopressin receptor V2?

I was looking at the production of vasopressin receptor 2, also known as V2R or ADH-R. What I found is that it is coded by the AVPR2 gene and degraded by the Alix protein (source). But I did not get ...
2
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1answer
67 views

What happens to IP3 molecules after release from IP3 receptors?

IP3 molecules bind to IP3 receptors and open up the calcium channels on the endoplasmic reticulum. I am wondering what happens to IP3 molecules after they have been released from the IP3 receptor? Do ...
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1answer
291 views

How do steroids travel in the bloodstream?

Cholesterol, which is hydrophobic, cannot simply travel in the bloodstream, and instead is enclosed in lipoprotein (LDL, HDL). Steroids, which are derived from cholesterol, are also hydrophobic (right?...
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3answers
242 views

How can a ligand be an integral membrane protein?

My background is in mathematics, and not biology, so please bear with me. I am currently working on a project involving the effects of Epidermal growth factor treatment (EGF) on cell migration. I am ...
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0answers
58 views

When and How do pacemaker cells develop during the cell aggregation process of Dictyostelium discoideum?

I was reading a paper by Tang & Othmer about oscillations and waves in Dictyostelium discoideum. Under certain condition like starvation period in the life cycle of a Dictyostelium discoideum ...
5
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1answer
209 views

Why does a “cascade” of events happen during signal transduction?

I've been watching some videos on signal transduction and it says that because there are enzymes being activated by the signal, then there is a "cascade" which happens afterwards...I don't understand ...
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2answers
582 views

Effect of steroid hormone on specific cells?

As steroid hormones can pass through the plasma membrane by simple diffusion because they are lipid derived hormones, it means that they are capable of passing through every cell of our body, BUT why ...
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5answers
125 views

Can your immune system's cells destroy you? (Critical thinking and Fictional sense)

In an imaginary sense, If you alone were replicated into 2 so that there should now be 2 of "you" (meaning you both have the same DNA). Then let's say one of you shrunk to the size of a bacteria, and ...
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2answers
118 views

Does the cellular response to every receptor work the same way?

I heard somewhere that activating any receptor results in the same intracellular response (signaling) which involves NF-κB. If that is true, I hardly understand how the cells distinguish between ...
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4answers
232 views

Specificity of Protein Kinases in Signaling Pathways..?

In most of the signaling pathways the activated receptor when activates Protein Kinase through the action of secondary messenger, then these protein kinases almost always phosphorylate on the specific ...
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1answer
47 views

What's the duration between the binding of adrenaline to β-AR and the first translated protein?

Binding of adrenaline (epinephrine) to the β-Adrenergic receptor leads to formation of cAMP (via G protein activation), activation of protein kinase A and subsequently to the expression of specific ...
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1answer
536 views

Apoptosis vs necroptosis

I understand that apoptosis and necroptosis share the same upper part of the pathway, but I cannot seem to distinguish when is each one activated? From my readings, it seems that when procaspases 8 or ...
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2answers
267 views

How does the cell regulate different metabolic pathways?

I heard somewhere that cells use different nucleosides bound to triphosphates e.g. ATP, GTP, CTP and other modified compounds: NADH, NADPH to distinguish between different metabolic pathways and so ...
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2answers
135 views

Localization of Protein Kinase-A

Is protein kinase-A located in the cytosol/cytoplasm of cells or in the plasma membrane? Also, is it considered a receptor molecule since it is dependent on cAMP? Any and all help is appreciated. ...
2
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1answer
191 views

What is the functional significance of the difference in cardiolipin/cholesterol ratio in different membranes?

I have read somewhere that the plasma membrane has little cardiolipin but excess cholesterol whereas the inner mitochondrial membrane is rich in cardiolipin and has little cholesterol.I just wanted to ...
4
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1answer
307 views

which signalling pathway is involved in cancer?

Columnar epithelial cells from the colonic mucosa are studied to identify abnormalities in cell signaling pathways. Abnormal epithelial cells from colonic adenocarcinoma are shown to have a mutation ...
2
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1answer
70 views

Why do oncogenes show genetic dominance?

As we know that tumor suppressor gene causes cancer only when both the alleles are recessive in nature.But in case of oncogenes if only one allele is dominant it can cause cancer.Why in case of ...
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1answer
40 views

Modern research or study on patterns in nerve signals

I am trying to find any recent study on pattern recognition in nerve signals. It does not really matter the part of the body where the research is focused on. It can be anything from studying activity ...
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2answers
274 views

Effect of testosterone hormone on cell signalling and behaviour?

A steroid, testosterone was injected in female body which led to development of secondary sexual characters but these characters were not developed over night (Response was very slow). What could be ...
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1answer
53 views

Regarding signalling pathways

Do all signalling pathways have something that can inhibit them? If the signal pathway is benefitial and it is inhibited would the inhibitor be caused by a biological problem? Are all inhibitors ...
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2answers
1k views

Why does Hunger lead to the aggressive behavior?

I have observed that frequently when people are hungry; they tend to get angry more easily on pointless issues. Does this mean that our fight or flight response is more active when a person is hungry? ...
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1answer
80 views

Can (any) human cells learn?

I'm not talking about single celled organisms, but actual cells in your body. Is there any evidence that they can learn to, say, navigate an environment or avoid an aversive stimulus like an animal ...
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4answers
113 views

Exocytosis of mast cell secretory granules

I've been doing a bit of reading about mast cell degranulation and have become thoroughly lost while trying to understand how the secretory granules are actually secreted. I understand that there are ...
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1answer
280 views

How do GPCRs transmit a signal across the plasma membrane?

How do G-coupled protein receptors (GPCR) transmit signals through the plasma membrane? Links containing information about this and pictures will be very helpful.
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1answer
85 views

Why can't intermediate filaments be used as tracks by motor proteins?

A motor protein like kinesin-1 cannot use an IF as a track because it lacks polarity. Can someone elaborate on this answer?
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1answer
338 views

Meaning of “auto” in trans autophosphorylation?

Why this process called "auto"? Is it because each tyrosine kinase receptor subunit of the RTK dimer has the ability to phosphorylate tyrosine or other amino acid residue present in other subunit of ...
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1answer
221 views

Transverse diffusion of lipids in red blood cells

The membrane of a human erythrocyte has polarity: Phosphatidylethanolamine and phosphatidylserine are predominantly on the inner side. Phosphatidylcholine and sphingomyelin are predominantly on the ...
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1answer
108 views

What is a phospho-protein binding domain?

Is this just a domain that binds proteins that have been phosphorylated? And it mediates signalling between an activated/phosphorylated protein? How is this significant with BRCA1?
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2answers
384 views

Signaling through G protein Coupled Receptors?

There are two different cell lines but we do not know that these cell lines have Gs or Gi proteins, associated with their G-protein coupled receptors. If we wants to know about this. Can we design a ...
3
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1answer
145 views

Amino acid profile of GPCRs

You are studying cellular signalling through a newly identified GPCR. Specifically you’re working on a pair of newly identified GPCRs, GPCR-A and GPCR-B. Each binds the same small ligand, but ...
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1answer
232 views

Significance of lipids in biological membranes…?

Membranes are specifically designed by lipids to maintain internal hydrophilic environment in narrow range.There are hydrophobic amino acids among naturally occurring 20 amino acids and as well as ...
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1answer
58 views

Bilayer synthesis? [closed]

If we want to design a bilayer from Myristic acid (14 carbon fatty acid). The average bond length between C-C is 1.5 A. What will be average thickness of the membrane? Edited to include the OP ...
2
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1answer
89 views

Structure of biological membranes?

Integral membrane proteins have functional asymmetry i.e. they have two different domains of proteins performing different functions. these proteins have Tyr and Trp amino acid residues at the ...
2
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2answers
5k views

Explanation of the terms “downstream signaling” and “upstream signaling”

In molecular biology, what's the meaning of the terms "downstream signaling" and "upstream signaling"? What's the difference between them?