Evidence map›Paper›PMID 32885882›Full record

ArticleJournal of thrombosis and haemostasis : JTH2021

A serine loop in tissue factor mediates substrate selectivity by the tissue factor-factor VIIa complex.

Fabienne Birkle, James H Morrissey

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Article in Journal of thrombosis and haemostasis : JTH, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 6 papers.

0numbers the graph read from it
0cells of the map it votes in
6citing papers in PubMed
0.8field-weighted citation impact, top 25% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

6 citing papers in PubMed, 10 citations in OpenAlex.

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  6. How the tissue factor-VIIa complex keeps two substrates in the loop.Journal of thrombosis and haemostasis : JTH · 2021
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4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

2 authors at 1 institution in 1 country.

Fabienne BirkleDepartment of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI, USA.ORCID 0000-0003-0238-8865
James H MorrisseyDepartment of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI, USA.ORCID 0000-0002-1570-1569
University of Michigan · US

Funding

Toolkit for High-Resolution Structure and Dynamics of Functional LipidsR01GM123455 · NIGMS · UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN · PI MORRISSEY, JAMES H., RIENSTRA, CHAD M · 2016 to 2020
$5.0M
Mechanisms in Blood ClottingR35HL135823 · NHLBI · UNIVERSITY OF MICHIGAN AT ANN ARBOR · PI MORRISSEY, JAMES H. · 2017 to 2023
$4.8M
NHLBI NIH HHS R35 HL135823NIGMS NIH HHS R01 GM123455
6 · The paper itself

Abstract

Essentials How the tissue factor-factor VIIa complex selects between different substrates is not well understood. We investigated a serine loop in tissue factor and its role in substrate selectivity. The tissue factor serine loop is selective for factor X over factor IX. Substrate selectivity is facilitated by differential regulation of the nearby tissue factor exosite. ABSTRACT: Background The tissue factor-factor VIIa (TF-FVIIa) complex is the physiologic activator of blood clotting and plays a major role in many thrombotic diseases. TF-FVIIa drives clotting through proteolytic cleavage of its major protein substrates, factor IX (FIX) and factor X (FX). However, it remains unclear how TF-FVIIa exhibits selectivity between these substrates. We previously showed that TF residues adjacent to the putative substrate binding site of TF ("exosite") facilitate FX activation, but the role of these residues in substrate selectivity had not been tested. Objectives We hypothesized that a TF serine loop (residues S160-S163) mediates substrate selectivity by the TF-FVIIa complex. Methods We generated TF serine loop and exosite mutants. The mutants were tested in FIX and FX enzyme activation assays as well as thrombin generation assays. Results Changes in the length of the serine loop affected rates of FIX and FX activation very differently. FX activation was decreased by up to 200-fold when the loop length was changed by just one residue. In contrast, FIX activation was largely unaffected. Substrate selectivity was also detected in thrombin generation assays. Activation assays with TF serine loop and exosite double mutants revealed that the serine loop has no effect on the exosite during FIX activation. In contrast, the serine loop regulates the exosite during FX activation. Conclusions Our results provide new insights into how the TF-FVIIa complex actively selects between its major protein substrates, which is mediated by a TF serine loop.

Indexed as

Factor VIIaThromboplastinFactor IXFactor XHumansSerineFactor IXFactor VIIaFactor XSerineThromboplastinfactor IXfactor Xserinethrombosistissue factor

Identifiers

PMID32885882
PMCPMC7790960
OpenAlexW3083274462

What OpenQuestion holds

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.