Related Experiment Video

Updated: May 24, 2026

Extracellular Vesicle Tissue Factor Activity Assay
03:53

Extracellular Vesicle Tissue Factor Activity Assay

Published on: December 29, 2023

TFPI-dependent activities of protein S

Sameera Peraramelli1, Jan Rosing, Tilman M Hackeng

  • 1Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), University Maastricht, The Netherlands.

Thrombosis Research
|March 20, 2012
PubMed

Insights

Protein S is a key anticoagulant protein. It enhances the activity of tissue factor pathway inhibitor (TFPI) and activated protein C (APC), crucial for regulating blood coagulation.

Area of Science:

  • Biochemistry
  • Hematology
  • Molecular Biology

Background:

  • Protein S is an essential anticoagulant protein.
  • It functions as a cofactor for tissue factor pathway inhibitor (TFPI) and activated protein C (APC).
  • Protein S enhances APC-mediated inactivation of coagulation factors Va and VIIIa and stimulates TFPI inhibition of FXa.

Purpose of the Study:

  • To explain how the TFPI/protein S system regains activity at high tissue factor concentrations.
  • To elucidate the intertwinement of TFPI- and APC-cofactor activities of protein S.
  • To highlight TFPI as a major determinant of APC anticoagulant activity in plasma.

Main Methods:

  • This is a review article, synthesizing existing research.
  • Analysis of the functional interplay between Protein S, TFPI, and APC.
  • Examination of coagulation regulation under varying tissue factor concentrations.

Main Results:

  • The TFPI/protein S system's anticoagulant activity is restored at high tissue factor concentrations when APC is present.
  • Protein S exhibits intertwined TFPI- and APC-cofactor activities.
  • TFPI becomes a significant determinant of APC's anticoagulant function in plasma.

Conclusions:

  • Protein S plays a critical, multifaceted role in regulating coagulation.
  • The interaction between Protein S, TFPI, and APC is complex and concentration-dependent.
  • Understanding these interactions is vital for comprehending anticoagulant mechanisms.

More Related Videos

Isolation of Physiologically Active Thylakoids and Their Use in Energy-Dependent Protein Transport Assays12:25

Isolation of Physiologically Active Thylakoids and Their Use in Energy-Dependent Protein Transport Assays

Published on: September 28, 2018

Utilizing Thermal Shift Assay to Probe Substrate Binding to Selenoprotein O03:09

Utilizing Thermal Shift Assay to Probe Substrate Binding to Selenoprotein O

Published on: August 9, 2024

Related Concept Videos

Mechanical Protein Functions01:58

Mechanical Protein Functions

Proteins perform many mechanical functions in a cell. These proteins can be classified into two general categories- proteins that generate mechanical forces and proteins that are subjected to mechanical forces. Proteins providing mechanical support to the structure of the cell, such as keratin, are subjected to mechanical force, whereas proteins involved in cell movement and transport of molecules across cell membranes, such as an ion pump, are examples of generating mechanical force. 
Cotranslational Protein Translocation01:20

Cotranslational Protein Translocation

Translocation of proteins across membranes is an ancient process that occurs even in bacteria and archaebacteria. In fact, the components of the translocation machinery are still conserved between prokaryotes and eukaryotes.
Sec61 channel partners for cotranslational translocation
During cotranslational translocation, the Sec61 channel partners with the signal recognition particle (SRP), the signal recognition particle receptor (SR), and the ribosomes to transport the nascent polypeptide chain...
The JAK-STAT Signaling Pathway01:20

The JAK-STAT Signaling Pathway

Several cytokine receptors have tightly bound Janus kinase or JAK proteins attached at their cytosolic tail. Small signaling molecules such as cytokines, growth hormones, or prolactins bind to the cytokine receptors and initiate their dimerization. The dimerization brings the cytosolic JAKs together that trans-phosphorylate and activates each other. The activated JAKs now phosphorylate cytosolic tails of the cytokine receptors, which serve as binding sites for adaptor proteins such as  SH2...
Directing Proteins to the Rough Endoplasmic Reticulum01:34

Directing Proteins to the Rough Endoplasmic Reticulum

The organelle-specific signaling sequences direct proteins synthesized in the cytosol to their final destination like ER, mitochondria, peroxisomes, etc. Some of the proteins directed to ER are then trafficked via vesicles to other organelles within the cell or the extracellular environment through the Golgi complex. For example, the rough ER synthesizes soluble proteins for transportation to the lysosomes or secretion out of the cell. It can also synthesize transmembrane proteins that can...
Structural Protein Function01:56

Structural Protein Function

Structural proteins are a category of proteins responsible for functions ranging from cell shape and movement to providing support to major structures such as bones, cartilage, hair, and muscles. This group includes proteins such as collagen, actin, myosin, and keratin.
Collagen, the most abundant protein in mammals, is found throughout the body. In connective tissue, such as skin, ligaments, and tendons, it provides tensile strength and elasticity.  In bones and teeth, it mineralizes to form...
Structural Protein Function01:56

Structural Protein Function

Structural proteins are a category of proteins responsible for functions ranging from cell shape and movement to providing support to major structures such as bones, cartilage, hair, and muscles. This group includes proteins such as collagen, actin, myosin, and keratin.
Collagen, the most abundant protein in mammals, is found throughout the body. In connective tissue, such as skin, ligaments, and tendons, it provides tensile strength and elasticity.  In bones and teeth, it mineralizes to form...