THE "CHELOID FACTOR" AT THE CELLULAR MEMBRANE!

We tend to be excited about intracellular pathways as they travel through the Cytosol and affect epigenetic and nuclear phenomena. And our excitement has been justified since we have been able to affect cellular life by targeting various pathway molecules.  But one should stress a particular event occurring at the membrane that mimics "wound phenomena".  Aside for providing a physical boundary of the cell, the membrane is one of the most important "organs" of the cell.  It is in itself a very chemically vibrant living "cellular tissue ".  When you start reading about the cell they tell you about the layers of proteins and lipids that make up the cellular membranes.  But this picture is far from the truth, the membrane is like the wall of a brick house.  With each brick different from the next.  Some of these bricks are called Integrins (I guess because they are an integral part of the membrane).  Some of these bricks have a Cyclin, some have a growth factor!  In fact, the membrane here serves as a reserve of these molecules. Some bricks can be divided in 2 portions.  One portion that can "FLIP" inside when needed (This portion contains the cyclin, for example) and one portion that can "FLOP" outside (this portion contains a Metalloprotease).  (see my post on FLIPPASE and FLOPPASE) The point is that once the brick is used there remains a hole with sharp edges.  These edges are called "FOCAL ADHESION Molecules" (KINASES) in a cell and are governed by the PTK2 gene!  (and of course PYK2)

PTK2:

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Protein tyrosine kinase 2
PDB rendering of the C-terminal FAT domain based on 1k04[1].
Available structures PDB Ortholog search: PDBe, RCSB [show]List of PDB id codes
Identifiers
Symbols	PTK2; FADK; FAK; FAK1; FRNK; PPP1R71; p125FAK; pp125FAK
External IDs	OMIM: 600758 MGI: 95481 HomoloGene: 7314 ChEMBL: 2695 GeneCards: PTK2 Gene
EC number	2.7.10.2
[show]Gene Ontology
RNA expression pattern
More reference expression data
Orthologs
Species	Human	Mouse
Entrez	5747	14083
Ensembl	ENSG00000169398	ENSMUSG00000022607
UniProt	Q05397	P34152
RefSeq (mRNA)	NM_001199649	NM_001130409
RefSeq (protein)	NP_001186578	NP_001123881
Location (UCSC)	Chr 8: 141.67 – 142.01 Mb	Chr 15: 73.21 – 73.42 Mb
PubMed search	[1]	[2]

PTK2 protein tyrosine kinase 2 (PTK2), also known as Focal Adhesion Kinase (FAK), is a protein that, in humans, is encoded by the PTK2 gene.^[2] PTK2 is a focal adhesion-associated protein kinase involved in cellular adhesion (how cells stick to each other and their surroundings) and spreading processes (how cells move around).^[3] It has been shown that when FAK was blocked, breast cancer cells became less metastastic due to decreased mobility.<sup>[4](Wikepedia
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AND THEY ARE PLENTY TALKED ABOUT! 
===============================================================  I.E....</sup>

"Integrin-dependent translocation of phosphoinositide 3-kinase to the cytoskeleton of thrombin-activated platelets involves specific interactions of p85 alpha with actin filaments and focal adhesion kinase(JCB)"

 

The point is that at the membrane healing should occur after the "integrin" has been plucked off, but failure to heal may trigger the "cheloid effect".  In the cell, this is where the Src gene is, the Wnt (catenins) and the Notch are here, Caspase 3 is present, and death Receptors,etc... (things can get complicated really fast with these guys around! unless of course phosphorylation or other taming mechanisms come to play!)

Focal Adhesion kinases (FAK)

". FAK is typically located at structures known as focal adhesions, these are multi-protein structures that link the extracellular matrix (ECM) to the cytoplasmic cytoskeleton. Additional components of focal adhesions include actin, filamin, vinculin, talin, paxillin, tensin^[7] and RSU-1."  This is what Taxol and Taxotere find their might!  (components of microtubules)

remember tensin is same as PTEN

NIH

" PTEN1

Also known as

BZS; DEC; CWS1; GLM2; MHAM; TEP1; MMAC1; PTEN1; 10q23del

Summary

This gene was identified as a tumor suppressor that is mutated in a large number of cancers at high frequency. The protein encoded this gene is a phosphatidylinositol-3,4,5-trisphosphate 3-phosphatase. It contains a tensin like domain as well as a catalytic domain similar to that of the dual specificity protein tyrosine phosphatases. Unlike most of the protein tyrosine phosphatases, this protein preferentially dephosphorylates phosphoinositide substrates. It negatively regulates intracellular levels of phosphatidylinositol-3,4,5-trisphosphate in cells and functions as a tumor suppressor by negatively regulating AKT/PKB signaling pathway. [provided by RefSeq, Jul 2008]"

NON-CASPASE WAY TO CELL DEATH
ONE OF THE WAYS CELLS DIE WHICH IS NON-CASPASE DRIVEN MAY RESULT FROM DISRUPTION TO THE CONCENTRATION OF THE CYTOSOL OR SOLUTION WITHIN THE CELL.   HOMEOSTASIS REQUIRES THAT SOLUTION TO BE SET AT A CERTAIN CONCENTRATION IN TERMS OF ELECTROLYTES, OXYGEN AND PH.  THE CELL HAS ION PUMPS TO MAINTAIN ELECTROLYTE CONCENTRATION.  ELECTIVE DISRUPTION OF ION PUMPS WILL LEAD TO DISRUPTION OF CONCENTRATIONS THAT MAY SEND DEVASTATING BLOW TO THE CELL.   WATER GOES FROM LESS CONCENTRATED TO MORE CONCENTRATED ENVIRONMENTS.  THIS IS A POWERFUL KNOWN LAW OF NATURE.  IN CLINICAL PRACTICE, WE DON'T USE THIS LAW ENOUGH.  NOT BECAUSE IT IS NOT REAL
BECAUSE THIS IS HOW DIABETES KILLS ITS VICTIMS.  THIS IS HOW DEHYDRATION KILLS AND SO ON.   OUR CHALLENGE HAS BEEN HOW TO ELECTIVELY USE IT TO ATTACK ONLY CANCER CELLS.  FOR THIS WE NEED TO FIND OUT IF IONS PUMPS FROM CANCER CELLS ARE DIFFERENT FROM THOSE OF NORMAL CELLS.

(TO BE CONTINUED)

Lysosome

Hypothesis for cancer research

In the cell there is a small body covered by a membrane called Lysosome.
This body is full of enzymes capable of causing death to the cell should the enzyme (Acid hydrolase) get released in the intracellular solution.  Acid Hydrolase and related enzymes are powerfully destructive but they only act in a very acid environment.  When they come out mistakenly, the neutral state of the Cytosol (intracellular solution where all the organelles of the cell are floating)  paralyzes these enzymes.  The reason why the inside of the lysosome can stay very Acid to allow the function of these enzymes is linked to the existence in the lysosomal membranes  of proton pumps forcing hydrogen ions into the lysosome.  Scientists are looking at paralyzing these proton pumps in cancer cells in order to disturb selectively lysosomal function of targeted cancer cells.  Just changing the Ph of the cell to a more Acidic environment could kill the cell by affecting the many metabolic reactions that only occur effectively at neutral Ph.

Also in this structure (lysosome) there are other targets such the mannose Monophosphate receptors which, if successfully paralyzed, could also induce various lysosomal disturbances.  Weakening cancer cells could cure one from cancer.  The struggle continues.