Search AllFam [Help]
Go!

• AllFam Home
• Browse AllFam
• Help/FAQ
• About AllFam
• References

Powered by

Medical University of Vienna > AllFam > Browse > Allergen family description

AF007: EF hand family

Biochemical properties

A wide range of calcium-binding proteins share a conserved domain consisting of a 12 residue calcium-binding loop flanked on both sides by α-helices of 12 residues in length. The biological functions of these proteins can be divided into two classes: signaling and calcium buffering or transport. Signaling proteins such as calmodulin and troponin C undergo a conformational change upon calcium binding [1].

Allergens from this family

Several groups of allergens were found within this family.

• Polcalcins: Polcalcins are 9 kDa calcium-binding pollen-specific proteins suggested to be involved in pollen germination and pollen tube growth [2]. While regular polcalcins contain two EF hand domains, several polcalcin-related allergens with three or four EF hand domains were described [3]. Polcalcins were shown to be minor albeit highly cross-reactive allergens identified in pollen from diverse plant families [4].
• Parvalbumins: Parvalbumins are 12 kDa proteins containing two EF hand domains. They are found in fast-twitch muscle fibers of vertebrates and bind Ca²⁺ during muscle relaxation [5]. Parvalbumins from fishes and amphibians are major food allergens eliciting IgE reponses in most fish-allergic individuals [6]. Parvalbumins from higher vertebrates have not been shown to bind human IgE.
• Troponin C: Troponin is a muscle protein that binds to the thin filaments and initiates muscle contraction upon binding of Ca²⁺ [5]. Troponin is a complex of three proteins, Ca²⁺ binding (troponin C), inhibitory (troponin I), and tropomyosin binding (troponin T). Allergens from this family were found in cockroaches and crustaceans (group 6 allergens) [7, 8].
• Sarcoplasmic calcium binding proteins: The invertebrate muscle proteins were proposed to exert a calcium buffering function similar to that of parvalbumins in vertebrate muscle [9]. Members of this family were described as allergens in crustaceans [8, 10].
• Myosin light chain: The myosin molecule is a multi-subunit complex made up of two heavy chains and four calcium-binding light chains. It is a fundamental contractile protein found in all eukaryote cell types. Myosin light chain from invertebrates, such as crustaceans and cockroaches were shown to bind IgE [8].

The IgE binding capacity of some EF hand-containing allergens was shown to be calcium-dependent.

[top]

References

1. Gifford JL, Walsh MP, Vogel HJ:
   Structures and metal-ion-binding properties of the Ca2+-binding helix-loop-helix EF-hand motifs.
   Biochem J 2007, 405, 199-221. [PubMed] [Full Text]
2. Okada T, Sasaki Y, Ohta R, Onozuka N, Toriyama K:
   Expression of Bra r 1 gene in transgenic tobacco and Bra r 1 promoter activity in pollen of various plant species.
   Plant Cell Physiol 2000, 41, 757-66. [PubMed]
3. Wopfner N, Gruber P, Wallner M, Briza P, Ebner C, Mari A, Richter K, Vogel L, Ferreira F:
   Molecular and immunological characterization of novel weed pollen pan-allergens.
   Allergy 2008, 63, 872-81. [PubMed] [Full Text]
4. Ledesma A, Barderas R, Westritschnig K, Quiralte J, Pascual CY, Valenta R, Villalba M, Rodriguez R:
   A comparative analysis of the cross-reactivity in the polcalcin family including Syr v 3, a new member from lilac pollen.
   Allergy 2006, 61, 477-84. [PubMed] [Full Text]
5. Berchtold MW, Brinkmeier H, Muntener M:
   Calcium ion in skeletal muscle: its crucial role for muscle function, plasticity, and disease.
   Physiol Rev 2000, 80, 1215-65. [PubMed]
6. Kuehn A, Swoboda I, Arumugam K, Hilger C, Hentges F:
   Fish allergens at a glance: variable allergenicity of parvalbumins, the major fish allergens.
   Front Immunol 2014, 5, 179. [PubMed] [Full Text]
7. Hindley J, Wunschmann S, Satinover SM, Woodfolk JA, Chew FT, Chapman MD, Pomes A:
   Bla g 6: a troponin C allergen from Blattella germanica with IgE binding calcium dependence.
   J Allergy Clin Immunol 2006, 117, 1389-95. [PubMed] [Full Text]
8. Pedrosa M, Boyano-Martinez T, Garcia-Ara C, Quirce S:
   Shellfish Allergy: a Comprehensive Review.
   Clin Rev Allergy Immunol 2015, 49, 203-16. [PubMed] [Full Text]
9. Gao Y, Gillen CM, Wheatly MG:
   Molecular characterization of the sarcoplasmic calcium-binding protein (SCP) from crayfish Procambarus clarkii.
   Comp Biochem Physiol B Biochem Mol Biol 2006, 144, 478-87. [PubMed] [Full Text]
10. Ayuso R, Grishina G, Ibanez MD, Blanco C, Carrillo T, Bencharitiwong R, Sanchez S, Nowak-Wegrzyn A, Sampson HA:
    Sarcoplasmic calcium-binding protein is an EF-hand-type protein identified as a new shrimp allergen.
    J Allergy Clin Immunol 2009, 124, 114-20. [PubMed] [Full Text]

[top]

Links to Pfam

Family-defining Pfam domains (at least one of these domains is present in each family member):

Pfam domain		Pfam clan
PF00036	EF hand	CL0220	EF-hand like superfamily
PF01023	S-100/ICaBP type calcium binding domain	CL0220	EF-hand like superfamily
PF13202	EF hand	CL0220	EF-hand like superfamily
PF13405	EF-hand domain	CL0220	EF-hand like superfamily
PF13499	EF-hand domain pair	CL0220	EF-hand like superfamily
PF13833	EF-hand domain pair	CL0220	EF-hand like superfamily

Additional Pfam domains found in some family members:

Pfam domain		Pfam clan
PF01221	Dynein light chain type 1	-

Links to Wikipedia

• EF hand
• Parvalbumin
• Troponin C

[top]

If you have updates or corrections for this entry, please contact the site administrator: christian.radauer@meduniwien.ac.at .