Calponin homology domain (or CH domain) is a family of

actin Actin is a family of globular multi-functional proteins that form microfilaments in the cytoskeleton, and the thin filaments in muscle fibrils. It is found in essentially all eukaryotic cells, where it may be present at a concentration of over ...

binding domains found in both cytoskeletal proteins and signal transduction proteins. The domain is about 100 amino acids in length and is composed of four alpha helices. It comprises the following groups of actin-binding domains: *

Actinin Actinin is a microfilament protein. Alpha-actinin-1 is necessary for the attachment of actin myofilaments to the Z-lines in skeletal muscle cells, and to the dense bodies in smooth muscle cells. The functional protein is an anti-parallel dimer, ...

-type (including spectrin, fimbrin, ABP-280) *

Calponin Calponin is a calcium binding protein. Calponin tonically inhibits the ATPase activity of myosin in smooth muscle. Phosphorylation of calponin by a protein kinase, which is dependent upon calcium binding to calmodulin, releases the calponin's ...

-type A comprehensive review of proteins containing this type of actin-binding domains is given in. The CH domain is involved in actin binding in some members of the family. However, in calponins there is evidence that the CH domain is not involved in its actin binding activity. Most proteins have two copies of the CH domain, however some proteins such as calponin and the human vav proto-oncogene () have only a single copy. The structure of an example CH domain has been determined using

X-ray crystallography X-ray crystallography is the experimental science determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to diffract into many specific directions. By measuring the angles ...

Examples

Human genes encoding calponin homology domain-containing proteins include: *

ACTN1 Alpha-actinin-1 is a protein that in humans is encoded by the ''ACTN1'' gene. Function Alpha actinins belong to the spectrin gene superfamily which represents a diverse group of cytoskeletal proteins, including the alpha and beta spectrins an ...

ACTN2 Alpha-actinin-2 is a protein which in humans is encoded by the ''ACTN2'' gene. This gene encodes an alpha-actinin isoform that is expressed in both skeletal and cardiac muscles and functions to anchor myofibrillar actin thin filaments and titin to ...

ACTN3 Alpha-actinin-3, also known as alpha-actinin skeletal muscle isoform 3 or F-actin cross-linking protein, is a protein that in humans is encoded by the ''ACTN3'' gene (named sprinter gene, speed gene or athlete gene) located on chromosome 11. All ...

ACTN4 Alpha-actinin-4 is a protein that in humans is encoded by the ''ACTN4'' gene. Alpha actinins belong to the spectrin gene superfamily which represents a diverse group of cytoskeletal proteins, including the alpha and beta spectrins and dystrophins ...

, ARHGEF6, ARHGEF7, ASPM, * CLMN,

CNN1 Calponin 1 is a basic smooth muscle protein that in humans is encoded by the ''CNN1'' gene. The ''CNN1'' gene is located at 19p13.2-p13.1 in the human chromosomal genome and contains 7 exons, encoding the protein calponin 1, an actin filament-as ...

CNN2 Calponin 2 is a protein that in humans is encoded by the ''CNN2'' gene. The ''CNN2'' gene is located at 19p13.3 in the human chromosomal genome, encoding the protein calponin 2. Calponin 2 is one of the three isoforms of calponin and an actin fi ...

, CNN3, *

DIXDC1 Dixin is a protein that in humans is encoded by the ''DIXDC1'' gene. When active it stops cancer metastasis Metastasis is a pathogenic agent's spread from an initial or primary site to a different or secondary site within the host's body; the ...

, DMD,

DST Daylight saving time (DST), also referred to as daylight savings time or simply daylight time (United States, Canada, and Australia), and summer time (United Kingdom, European Union, and others), is the practice of advancing clocks (typicall ...

, * EHBP1, EHBP1L1, *

FLNA Filamin A, alpha (FLNA) is a protein that in humans is encoded by the ''FLNA'' gene. Function Actin-binding protein, or filamin, is a 280-kD protein that crosslinks actin filaments into orthogonal networks in cortical cytoplasm and participate ...

FLNB Filamin B, beta (FLNB), also known as Filamin B, beta (truncated actin binding protein 278 homolog), is a cytoplasmic protein which in humans is encoded by the ''FLNB'' gene. FLNB regulates intracellular communication and signalling by cross-linki ...

FLNC The National Liberation Front of Corsica ( co, Fronte di liberazione naziunale di a Corsica or ; french: Front de libération nationale corse, abbreviated FLNC) was a militant group that advocates an independent state on the island of Corsica, se ...

, * GAS2, GAS2L1,

GAS2L2 Gas is one of the four fundamental states of matter (the others being solid, liquid, and plasma). A pure gas may be made up of individual atoms (e.g. a noble gas like neon), elemental molecules made from one type of atom (e.g. oxygen), or com ...

, GAS2L3, *

IQGAP1 Ras GTPase-activating-like protein IQGAP1 (IQGAP1) also known as p195 is a ubiquitously expressed protein that in humans is encoded by the ''IQGAP1'' gene. IQGAP1 is a scaffold protein involved in regulating various cellular processes ranging from ...

IQGAP2 Ras GTPase-activating-like protein IQGAP2 is an enzyme that in humans is encoded by the ''IQGAP2'' gene. Function This gene encodes a member of the IQGAP family. The protein contains three IQ domains, one calponin homology domain, one Ras-GAP ...

, IQGAP3, *

LCP1 Plastin-2 is a protein that in humans is encoded by the ''LCP1'' gene. Function Plastins are a family of actin-binding proteins that are conserved throughout eukaryote evolution and expressed in most tissues of higher eukaryotes. In humans, t ...

, LIMCH1, LMO7, LRCH1, LRCH2, LRCH3, LRCH4, *

MACF1 Microtubule-actin cross-linking factor 1, isoforms 1/2/3/5 is a protein that in humans is encoded by the ''MACF1'' gene. MACF1 encodes a large protein containing numerous spectrin and leucine-rich repeat (LRR) domains. MACF1 is a member of a fami ...

MAPRE1 Microtubule-associated protein RP/EB family member 1 is a protein that in humans is encoded by the ''MAPRE1'' gene. Function The protein encoded by this gene was first identified by its binding to the APC (Adenomatous polyposis coli) protein w ...

MAPRE2 Microtubule-associated protein RP/EB family member 2 is a protein that in humans is encoded by the ''MAPRE2'' gene. Function The protein encoded by this gene shares significant homology to the adenomatous polyposis coli (APC) protein-binding EB ...

MAPRE3 Microtubule-associated protein RP/EB family member 3 is a protein that in humans is encoded by the ''MAPRE3'' gene. The protein encoded by this gene is a member of the RP/EB family of genes. The protein localizes to the cytoplasmic microtubule ...

MICAL1 NEDD9-interacting protein with calponin homology and LIM domains is a protein that in humans is encoded by the ''MICAL1'' gene. Interactions MICAL1 has been shown to interact with NEDD9 and RAB1A Ras-related protein Rab-1A is a protein that in ...

MICAL2 Protein MICAL-2 is a protein that in humans is encoded by the ''MICAL2'' gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' ...

, MICAL2PV1, MICAL2PV2,

MICAL3 Microtubule-associated monoxygenase, calponin and LIM domain containing 3, also known as MICAL3, is a human gene. Function Along with two other Rab proteins, Rab6 and Rab8, MICAL3 work together in the process of docking and fusing of vesicles t ...

, MICALL1, MICALL2, *

NAV2 Neuron navigator 2 is a protein that in humans is encoded by the ''NAV2'' gene. The vitamin A metabolite, all-trans retinoic acid (atRA), plays an important role in neuronal development, including neurite outgrowth. RAINB1 is an atRA-responsive ge ...

, NAV3, *

PARVA Parva may refer to: * PARVA, a gene * The 18 parvas, books or chapters of the ''Mahabharata'' * Parva (band), name of English band Kaiser Chiefs from 2000 to 2003 * ''Parva'' (2002 film), a Kannada language film by Sunil Kumar Desai * ''Parva'' ...

, PARVB, PARVG,

PLEC1 Plectin is a giant protein found in nearly all mammalian cells which acts as a link between the three main components of the cytoskeleton: actin microfilaments, microtubules and intermediate filaments. In addition, plectin links the cytoskelet ...

PLS1 Fimbrin also known as is plastin 1 is a protein that in humans is encoded by the PLS1 gene. Fimbrin is an actin cross-linking protein important in the formation of filopodia. Structure Fimbrin belongs to the calponin homology (biology), homolog ...

PLS3 Plastin-3 is a highly conserved protein that in humans is encoded by the ''PLS3'' gene on the X chromosome. Function Plastins are a family of actin-binding proteins that are conserved throughout eukaryote evolution and expressed in most tissu ...

, PP14183, *

SMTN Smoothelin is a protein that in humans is encoded by the ''SMTN'' gene. This gene encodes a structural protein that is found exclusively in contractile smooth muscle cells. It associates with stress fibers and constitutes part of the cytoskeleton ...

, SMTNL2, SPECC1, SPECC1L, SPNB4,

SPTB Spectrin beta chain, erythrocyte is a protein that in humans is encoded by the ''SPTB'' gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation ...

SPTBN1 Spectrin beta chain, brain 1 is a protein that in humans is encoded by the ''SPTBN1'' gene. Function Spectrin is an actin crosslinking and molecular scaffold protein that links the plasma membrane to the actin cytoskeleton, and functions in the ...

SPTBN2 Spectrin beta chain, brain 2 is a protein that in humans is encoded by the ''SPTBN2'' gene. Clinical significance Mutations in this gene is associated with Spinocerebellar ataxia type 5. Interactions SPTBN2 has been shown to interact with: * ...

SPTBN4 Spectrin, beta, non-erythrocytic 4, also known as SPTBN4, is a protein that in humans is encoded by the ''SPTBN4'' gene. Spectrin is an actin crosslinking and molecular scaffold protein that links the cell membrane to the actin cytoskeleton, and ...

SPTBN5 Spectrin, beta, non-erythrocytic 5 also known as SPTBN5 is a protein that in humans is encoded by the ''SPTBN5'' gene. SPTBN5 belongs to the spectrin family of cytoskeletal proteins. Structure and function SPTBN5 contains the following domain ...

SYNE1 Enaptin also known as nesprin-1 or synaptic nuclear envelope protein 1 (syne-1) is an actin-binding protein that in humans that is encoded by the SYNE1 gene. Function This gene encodes a spectrin repeat containing protein expressed in skeletal ...

SYNE2 Nesprin-2 is a protein that in humans is encoded by the ''SYNE2'' gene. The human SYNE2 gene consists of 116 exons and encodes nesprin-2, a member of the nuclear envelope (NE) spectrin-repeat (nesprin) family. Nesprins are modular proteins with a c ...

, *

TAGLN Transgelin is a protein that in humans is encoded by the ''TAGLN'' gene. The protein encoded by this gene is a transformation and shape-change sensitive actin cross-linking/gelling protein found in fibroblasts and smooth muscle. Its expression is ...

, TAGLN2, TAGLN3, *

UTRN Utrophin is a protein that in humans is encoded by the ''UTRN'' gene. The protein encoded by this gene is a component of the cytoskeleton. Utrophin was found during research into Duchenne's muscular dystrophy. The name is a contraction for ''ubiq ...

, and *

VAV1 Proto-oncogene vav is a protein that in humans is encoded by the ''VAV1'' gene. Function The protein encoded by this proto-oncogene is a member of the Dbl family of guanine nucleotide exchange factors (GEF) for the Rho family of GTP binding pr ...

VAV2 Guanine nucleotide exchange factor VAV2 is a protein that in humans is encoded by the ''VAV2'' gene. VAV2 is the second member of the VAV oncogene family. Unlike VAV1, which is expressed exclusively in hematopoietic cells, VAV2 transcripts were f ...

VAV3 Guanine nucleotide exchange factor VAV3 is a protein that in humans is encoded by the ''VAV3'' gene. This gene is a member of the VAV gene family. The VAV proteins are guanine nucleotide exchange factors (GEFs) for Rho family GTPases that activ ...

References

{{InterPro content, IPR001715 Protein domains