Shank

Shank is the lower part of the leg, also called the "shin".

Shank may also refer to:

Component parts

People

Shank (footwear)

In a boot or shoe, the shank is a part of the supportive structure between the insole and outsole. The presence of a shank is crucial to the functionality of mountaineering boots as they diminish the load incurred by the wearer’s feet and calves over the course of an ascent. Traditionally constructed of steel, contemporary shanks are more commonly made up of less heat conductive but equally rigid options such as fiberglass and Kevlar. The rigid nature of these materials contributes a protective element to the footwear into which they are integrated, helping shield the wearer’s feet from puncture wounds and stone bruises.

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Crook (music)

A crook, also sometimes called a shank, is an exchangeable segment of tubing in a natural horn (or other brass instrument, such as a natural trumpet) which is used to change the length of the pipe, altering the fundamental pitch and harmonic series which the instrument can sound, and thus the key in which it plays.

Master crook and coupler system

Early horns had unalterable lengths and permanently attached mouthpieces. This presented problems in concert situations. A different horn was required for different keys, and the instrument could not be tuned. Around 1700 the Leichnamschneider brothers in Vienna developed a horn with a removable mouthpiece which could be connected to a short piece of tubing, called a master crook. Additional pieces, couplers, of different length were inserted between the master crook and the body of the horn to change the horn's length, and thus the pitch. Fine tuning was done with even shorter segments called tuning bits. This simple and relatively inexpensive solution remained in use even into the 19th century. Charles Tully's Tutor for the French Horn, published in London, recommended this system for beginners as late as 1840.

ANK2

Ankyrin-B, also known as Ankyrin-2, is a protein which in humans is encoded by the ANK2 gene. Ankyrin-B is ubiquitously expressed, but shows high expression in cardiac muscle. Ankyrin-B plays an essential role in the localization and membrane stabilization of ion transporters and ion channels in cardiomyocytes, as well as in costamere structures. Mutations in ankyrin-B cause a dominantly-inherited, cardiac arrhythmia syndrome known as ankyrin-B syndrome as well as sick sinus syndrome; mutations have also been associated to a lesser degree with hypertrophic cardiomyopathy. Alterations in ankyrin-B expression levels are observed in human heart failure.

Structure

Ankyrin-B protein is around 220 kDa, with several isoforms. The ANK2 gene is approximately 560 kb in size and consists of 53 exons on human chromosome 4; ANK2 is also transcriptionally regulated via over 30 alternative splicing events with variable expression of isoforms in cardiac muscle. Ankyrin-B is a member of the ankyrin family of proteins, and is a modular protein which is composed of three structural domains: an N-terminal domain containing multiple ankyrin repeats; a central region with a highly conserved spectrin binding domain and death domain; and a C-terminal regulatory domain which is the least conserved and subject to variation, and determines ankyrin-B activity. The membrane-binding region of ankyrin-B is composed of 24 consecutive ankyrin repeats, and it is the membrane-binding domain of ankyrins that confer functional differences among ankyrin isoforms. Though ubiquitously expressed, ankyrin-B shows high expression levels in cardiac muscle, and is expressed 10-fold lower levels in skeletal muscle, suggesting that ankyrin-B plays a specifically adapted functional role in cardiac muscle.

ANK1

Ankyrin 1, erythrocytic, also known as ANK1, is a protein that in humans is encoded by the ANK1 gene.

Tissue distribution

The protein encoded by this gene, Ankyrin 1, is the prototype of the ankyrin family, was first discovered in erythrocytes, but since has also been found in brain and muscles.

Genetics

Complex patterns of alternative splicing in the regulatory domain, giving rise to different isoforms of ankyrin 1 have been described, however, the precise functions of the various isoforms are not known. Alternative polyadenylation accounting for the different sized erythrocytic ankyrin 1 mRNAs, has also been reported. Truncated muscle-specific isoforms of ankyrin 1 resulting from usage of an alternate promoter have also been identified.

Disease linkage

Mutations in erythrocytic ankyrin 1 have been associated in approximately half of all patients with hereditary spherocytosis.

ANK1 shows altered methylation and expression in Alzheimer's disease. A gene expression study of postmortem brains has suggested ANK1 interacts with interferon-γ signalling.

ANK3

Ankyrin-3 (ANK-3), also known as ankyrin-G, is a protein from ankyrin family that in humans is encoded by the ANK3 gene.

Function

The protein encoded by this gene, ankyrin-3 is an immunologically distinct gene product from ankyrins ANK1 and ANK2, and was originally found at the axonal initial segment and nodes of Ranvier of neurons in the central and peripheral nervous systems. Alternatively spliced variants may be expressed in other tissues. Although multiple transcript variants encoding several different isoforms have been found for this gene, the full-length nature of only two have been characterized.

Within the nervous system, ankyrin-G is specifically localized to the neuromuscular junction, the axon initial segment and the Nodes of Ranvier. Within the nodes of Ranvier where action potentials are actively propagated, ankyrin-G has long been thought to be the intermediate binding partner to neurofascin and voltage-gated sodium channels. The genetic deletion of ankyrin-G from multiple neuron types has shown that ankyrin-G is required for the normal clustering of voltage-gated sodium channels at the axon hillock and for action potential firing.