In molecular biology, Phosphotyrosine-binding domains are

protein domains In molecular biology, a protein domain is a region of a protein's polypeptide chain that is self-stabilizing and that folds independently from the rest. Each domain forms a compact folded three-dimensional structure. Many proteins consist of se ...

which bind to

phosphotyrosine -Tyrosine or tyrosine (symbol Tyr or Y) or 4-hydroxyphenylalanine is one of the 20 standard amino acids that are used by cells to synthesize proteins. It is a non-essential amino acid with a polar side group. The word "tyrosine" is from the G ...

. The phosphotyrosine-binding domain (PTB, also phosphotyrosine-interaction or PI domain) in the protein tensin tends to be found at the

C-terminus The C-terminus (also known as the carboxyl-terminus, carboxy-terminus, C-terminal tail, C-terminal end, or COOH-terminus) is the end of an amino acid chain (protein or polypeptide), terminated by a free carboxyl group (-COOH). When the protein i ...

. Tensin is a multi-domain protein that binds to

actin filaments Microfilaments, also called actin filaments, are protein filaments in the cytoplasm of eukaryotic cells that form part of the cytoskeleton. They are primarily composed of polymers of actin, but are modified by and interact with numerous other p ...

and functions as a focal-adhesion molecule (focal adhesions are regions of plasma membrane through which cells attach to the extracellular matrix).

Human Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...

tensin has

actin Actin is a protein family, family of Globular protein, globular multi-functional proteins that form microfilaments in the cytoskeleton, and the thin filaments in myofibril, muscle fibrils. It is found in essentially all Eukaryote, eukaryotic cel ...

-binding sites, an SH2 () domain and a region similar to the tumour suppressor PTEN. The PTB domain interacts with the

cytoplasmic In cell biology, the cytoplasm is all of the material within a eukaryotic cell, enclosed by the cell membrane, except for the cell nucleus. The material inside the nucleus and contained within the nuclear membrane is termed the nucleoplasm. T ...

tails of beta

integrin Integrins are transmembrane receptors that facilitate cell-cell and cell-extracellular matrix (ECM) adhesion. Upon ligand binding, integrins activate signal transduction pathways that mediate cellular signals such as regulation of the cell cycle, ...

by binding to an NPXY motif. The phosphotyrosine-binding domain of insulin receptor substrate-1 is not related to the phosphotyrosine-binding domain of tensin. Insulin receptor substrate-1

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respon ...

s contain both a

pleckstrin homology domain Pleckstrin homology domain (PH domain) or (PHIP) is a protein domain of approximately 120 amino acids that occurs in a wide range of proteins involved in intracellular signaling or as constituents of the cytoskeleton. This domain can bind phosp ...

and a phosphotyrosine binding (PTB) domain. The PTB domains facilitate

interaction Interaction is action that occurs between two or more objects, with broad use in philosophy and the sciences. It may refer to: Science * Interaction hypothesis, a theory of second language acquisition * Interaction (statistics) * Interaction ...

with the activated

tyrosine -Tyrosine or tyrosine (symbol Tyr or Y) or 4-hydroxyphenylalanine is one of the 20 standard amino acids that are used by cells to synthesize proteins. It is a non-essential amino acid with a polar side group. The word "tyrosine" is from the Gr ...

- phosphorylated insulin receptor. The PTB domain is situated towards the

N terminus The N-terminus (also known as the amino-terminus, NH2-terminus, N-terminal end or amine-terminus) is the start of a protein or polypeptide, referring to the free amine group (-NH2) located at the end of a polypeptide. Within a peptide, the amin ...

. Two

arginine Arginine is the amino acid with the formula (H2N)(HN)CN(H)(CH2)3CH(NH2)CO2H. The molecule features a guanidino group appended to a standard amino acid framework. At physiological pH, the carboxylic acid is deprotonated (−CO2−) and both the a ...

s in this domain are responsible for

hydrogen bonding In chemistry, a hydrogen bond (or H-bond) is a primarily electrostatic force of attraction between a hydrogen (H) atom which is covalently bound to a more electronegative "donor" atom or group (Dn), and another electronegative atom bearing ...

phosphotyrosine residues on an Ac-LYASSNPApY- NH2 peptide in the juxtamembrane region of the insulin receptor. Further interactions via "bridged" water molecules are coordinated by residues an Asn and a Ser residue. The PTB domain has a compact, 7-stranded beta-sandwich structure, capped by a C-terminal

helix A helix () is a shape like a corkscrew or spiral staircase. It is a type of smooth space curve with tangent lines at a constant angle to a fixed axis. Helices are important in biology, as the DNA molecule is formed as two intertwined hel ...

. The substrate

peptide Peptides (, ) are short chains of amino acids linked by peptide bonds. Long chains of amino acids are called proteins. Chains of fewer than twenty amino acids are called oligopeptides, and include dipeptides, tripeptides, and tetrapeptides. ...

fits into an L-shaped surface cleft formed from the C-terminal helix and strands 5 and 6.

Human proteins containing these domains

APBA1; APBA2; APBA3; APPL1; EPS8;

EPS8L1 Epidermal growth factor receptor kinase substrate 8-like protein 1 is an enzyme that in humans is encoded by the ''EPS8L1'' gene. This gene encodes a protein that is related to epidermal growth factor receptor pathway substrate 8 ( EPS8), a su ...

;

EPS8L2 Epidermal growth factor receptor kinase substrate 8-like protein 2 is an enzyme that in humans is encoded by the ''EPS8L2'' gene. This gene encodes a protein that is related to epidermal growth factor receptor pathway substrate 8 (EPS8), a subst ...

;

EPS8L3 Epidermal growth factor receptor kinase substrate 8-like protein 3 is an enzyme that in humans is encoded by the ''EPS8L3'' gene. This gene encodes a protein that is related to epidermal growth factor receptor pathway substrate 8 (EPS8), a subst ...

; TENC1; TNS; TNS1; TNS3; TNS4; DOK1;

DOK2 Lee Joon-kyung (; born March 28, 1990) better known by his stage name Dok2 (, pronounced as Dokki), is a South Korean rapper, record producer and co-founder of now-defunct Illionaire Records. Biography Early life Dok2's mother is Korean, and ...

; DOK3;

DOK4 Docking protein 4 is a protein that in humans is encoded by the ''DOK4'' gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth' ...

; DOK5; DOK6; DOK7; FRS2;

FRS3 Fibroblast growth factor receptor substrate 3 is a protein that in humans is encoded by the ''FRS3'' gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." mean ...

;

IRS1 Insulin receptor substrate 1 (IRS-1) is a signaling adapter protein that in humans is encoded by the ''IRS-1'' gene. It is a 131 kDa protein with amino acid sequence of 1242 residues. It contains a single pleckstrin homology (PH) domain at the N-t ...

; IRS2;

IRS4 Insulin receptor substrate 4 is a protein that in humans is encoded by the ''IRS4'' gene. IRS4 encodes the insulin receptor substrate 4, a cytoplasmic protein that contains many potential tyrosine and serine/threonine phosphorylation sites. Tyr ...

; NOS1AP; TLN1; TLN2

References

External links

* Protein domains Protein families Membrane proteins {{membrane-protein-stub

Human proteins containing these domains

See also

References

External links