Calponin homology domain explained

Calponin homology domain (or CH domain) is a family of actin binding domains found in both cytoskeletal proteins and signal transduction proteins.^[1] The domain is about 100 amino acids in length and is composed of four alpha helices.^[2] It comprises the following groups of actin-binding domains:

• Actinin-type (including spectrin, fimbrin, ABP-280)
• Calponin-type

A comprehensive review of proteins containing this type of actin-binding domains is given in.^[3]

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.^[4] 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.^[5]

Examples

Human genes encoding calponin homology domain-containing proteins include:

• ACTN1, ACTN2, ACTN3, ACTN4, ARHGEF6, ARHGEF7, ASPM,
• CLMN, CNN1, CNN2, CNN3,
• DIXDC1, DMD, DST,
• EHBP1, EHBP1L1,
• FLNA, FLNB, FLNC,
• GAS2, GAS2L1, GAS2L2, GAS2L3,
• IQGAP1, IQGAP2, IQGAP3,
• LCP1, LIMCH1, LMO7, LRCH1, LRCH2, LRCH3, LRCH4,
• MACF1, MAPRE1, MAPRE2, MAPRE3, MICAL1, MICAL2, MICAL2PV1, MICAL2PV2, MICAL3, MICALL1, MICALL2,
• NAV2, NAV3,
• PARVA, PARVB, PARVG, PLEC1, PLS1, PLS3, PP14183,
• SMTN, SMTNL2, SPECC1, SPECC1L, SPNB4, SPTB, SPTBN1, SPTBN2, SPTBN4, SPTBN5, SYNE1, SYNE2,
• TAGLN, TAGLN2, TAGLN3,
• UTRN, and
• VAV1, VAV2, VAV3

Notes and References

1. Saraste M, Castresana J . Does Vav bind to F-actin through a CH domain? . FEBS Lett. . 374 . 2 . 149–151 . 1995 . 7589522 . 10.1016/0014-5793(95)01098-Y. 29667309 .
2. Korenbaum . E. . Rivero . F. . Calponin homology domains at a glance. . J Cell Sci . 115 . Pt 18 . 3543–5 . Sep 2002 . 10.1242/jcs.00003. 12186940 . 10.1.1.608.8653 . 38137068 .
3. Hartwig JH . Actin-binding proteins. 1: Spectrin super family . Protein Prof. . 2 . 7 . 703–800 . 1995 . 7584474.
4. Gimona M, Mital R . The single CH domain of calponin is neither sufficient nor necessary for F-actin binding . J. Cell Sci. . 111 . 1813–1821 . 1998 . 9625744.
5. Saraste M, Carugo KD, Banuelos S . Crystal structure of a calponin homology domain . Nat. Struct. Biol. . 4 . 3 . 175–179 . 1997 . 9164454 . 10.1038/nsb0397-175. 1428195 .