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9  structures 273  species 0  interactions 1344  sequences 63  architectures

Family: MACPF (PF01823)

Summary: MAC/Perforin domain

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MACPF Edit Wikipedia article

MAC/Perforin domain
Identifiers
Symbol MACPF
Pfam PF01823
InterPro IPR001862
SMART MACPF
PROSITE PDOC00251
TCDB 1.C.39
Painting (acrylic on canvas) of the structure of the MACPF domain containing protein Plu-MACPF, by Dr Carla Chinni.[1][1].

The MACPF protein superfamily is named after a domain that is common to the Membrane Attack Complex proteins (MAC) of complement (C6, C7, C8α, C8β and C9) and perforin (PF). Many members of this protein family are important eukaryote pore forming toxins.[2]

The archetypal members of the family are complement C9 and perforin, both of which function in human immunity.[3] C9 functions by punching holes in the membrane of pathogenic Gram-negative bacteria. Perforin is released by cytotoxic T cells and lyses virally infected and transformed cells. In addition perforin permits delivery of cytotoxic proteases called granzymes that cause cell death.[4] Deficiency of either protein can result in human disease.[5][6] Structural studies reveal that MACPF domains are related to cholesterol dependent cytolysins (CDCs), a family of pore forming toxins previously thought to only exist in bacteria.[1][7]

Biological roles of MACPF domain containing proteins[edit]

To date, around 500 members of the MACPF superfamily have been identified. Many of these proteins play key roles in the plant and animal immunity.

The complement proteins C6-C9 all contain a MACPF domain and assemble into the membrane attack complex. C6, C7 and C8β appear to be non-lytic and function as scaffold proteins within the MAC. In contrast both C8α and C9 are capable of lysing cells. The final stage of MAC formation involves polymerisation of C9 into a large pore that punches a hole in the outer membrane of Gram negative bacteria.

Perforin is stored in granules within cytotoxic T-cells and is responsible for killing virally infected and transformed cells. Perforin functions via two distinct mechanisms. Firstly, like C9, high concentrations of perforin can form pores that lyse cells. Secondly, perforin permits delivery of the cytotoxic granzymes A and B into target cells. Once delivered, granzymes are able to induce apoptosis and cause target cell death.[4][8]

The plant protein CAD1 functions in the plant immune response to bacterial infection.[9]

The sea anemone Actineria villosa uses a MACPF protein as a lethal toxin.[10] MACPF proteins are also important for the invasion of the Malarial parasite into the mosquito host and the liver.[11][12]

Not all MACPF proteins function in defence or attack. For example, astrotactin is involved in neural cell migration in mammals and apextrin is involved in sea urchin (Heliocidaris erythrogramma) development.[13][14] Drosophila Torso-like protein, which controls embryonic patterning,[15] also contains a MACPF domain.[1] It is unknown whether the function of any of these proteins involves lytic activity.

Functionally uncharacterised MACPF proteins are sporadically distributed in bacteria. Several species of Chlamydia contain MACPF proteins.[16] The insect pathogenic bacteria Photorhabdus luminescens also contains a MACPF protein, however, this molecule appears non-lytic.[1]

Structure and mechanism[edit]

The X-ray crystal structure of Plu-MACPF, a protein from the insect pathogenic enterobacteria Photorhabdus luminescens has been determined (figure 1).[6] These data reveal that the MACPF domain is homologous to pore forming cholesterol dependent cytolysins (CDC's) from Gram positive pathogenic bacteria such as Clostridium perfringens (which causes gas gangrene). The amino acid sequence identity between the two families is extremely low, and the relationship is not detectable using conventional sequence based data mining techniques.[1]

It is suggested that MACPF proteins and CDCs form pores in the same way (figure 1).[1] Specifically it is hypothesised that MACPF proteins oligomerise to form a large circular pore (figure 2). A concerted conformational change within each monomer then results in two α-helical regions unwinding to form four amphipathic β-strands that span the membrane of the target cell.[1] Like CDC's MACPF proteins are thus β-pore forming toxins that act like a molecular hole punch.

Mechanism of membrane attack by MACPF proteins
Figure 1: a) The structure of the CDC perfringolysin O [17][2] and b) the structure of Plu-MACPF [1][3]. In both proteins the two small clusters of α-helicesl that are proposed to unwind and pierce the membrane are in pink.
Figure 2: Molecular model of the pre-pore form of a MACPF protein based upon the structure of pneunolysin.[18]

Control of MACPF proteins[edit]

Complement regulatory proteins such as CD59 function as MAC inhibitors and prevent inappropriate activity of complement against self cells (Figure 3). Biochemical studies have revealed the peptide sequences in C8α and C9 that bind to CD59.[19][20] Analysis of the MACPF domain structures reveals that these sequences map to the second cluster of helices that unfurl to span the membrane. It is therefore suggested that CD59 directly inhibits the MAC by interfering with conformational change in one of the membrane spanning regions.[1]

Other proteins that bind to the MAC include C8γ. This protein belongs to the lipocalin family and interacts with C8α. The binding site on C8α is known, however, the precise role of C8γ in the MAC remains to be understood.[21][22]

Proteins that bind MACPF domains
Figure 3: NMR structure of CD59.[23] [4].
Figure 3: Crystal structure of C8γ (green) with peptide from C8α (cyan).[22] [5].

Role in Human disease[edit]

Deficiency of C9, or other components of the MAC results in an increased susceptibity to diseases caused by Gram negative bacteria such as meningococcal meningitis.[24] Overactivity of MACPF proteins can also cause disease. Most notably, deficiency of the MAC inhibitor CD59 results in an overactivity of complement and Paroxysmal nocturnal hemoglobinuria.[25]

Perforin deficiency results in the commonly fatal disorder familial hemophagocytic lymphohistiocytosis (FHL or HLH).[5] This disease is characterised by an overactivation of lymphocytes which results in cytokine mediated organ damage.[26]

The MACPF protein DBCCR1 may function as a tumour suppressor in bladder cancer.[27]

Human proteins containing this domain[edit]

C6; C7; C8A; C8B; C9; FAM5B; FAM5C; MPEG1; PRF1

See also[edit]

References[edit]

  1. ^ a b c d e f g h i Rosado CJ, Buckle AM, Law RH, et al. (2007). "A Common Fold Mediates Vertebrate Defense and Bacterial Attack". Science 317 (5844): 1548–51. doi:10.1126/science.1144706. PMID 17717151. 
  2. ^ Peitsch MC, Tschopp J (1991). "Assembly of macromolecular pores by immune defense systems". Curr. Opin. Cell Biol. 3 (4): 710–6. doi:10.1016/0955-0674(91)90045-Z. PMID 1722985. 
  3. ^ Tschopp J, Masson D, Stanley KK (1986). "Structural/functional similarity between proteins involved in complement- and cytotoxic T-lymphocyte-mediated cytolysis". Nature 322 (6082): 831–4. doi:10.1038/322831a0. PMID 2427956. 
  4. ^ a b Voskoboinik I, Smyth MJ, Trapani JA (2006). "Perforin-mediated target-cell death and immune homeostasis". Nat. Rev. Immunol. 6 (12): 940–52. doi:10.1038/nri1983. PMID 17124515. 
  5. ^ a b Voskoboinik I, Sutton VR, Ciccone A, et al. (2007). "Perforin activity and immune homeostasis: the common A91V polymorphism in perforin results in both presynaptic and postsynaptic defects in function". Blood 110 (4): 1184–90. doi:10.1182/blood-2007-02-072850. PMID 17475905. 
  6. ^ Witzel-Schlömp K, Späth PJ, Hobart MJ, et al. (1997). "The human complement C9 gene: identification of two mutations causing deficiency and revision of the gene structure". J. Immunol. 158 (10): 5043–9. PMID 9144525. 
  7. ^ Michael A. Hadders, Dennis X. Beringer, and Piet Gros (2007). "Structure of C8-MACPF Reveals Mechanism of Membrane Attack in Complement Immune Defense". Science 317 (5844): 1552–1554. doi:10.1126/science.1147103. PMID 17872444. 
  8. ^ Kaiserman D, Bird CH, Sun J, et al. (2006). "The major human and mouse granzymes are structurally and functionally divergent". J. Cell Biol. 175 (4): 619–30. doi:10.1083/jcb.200606073. PMC 2064598. PMID 17116752. 
  9. ^ Morita-Yamamuro C, Tsutsui T, Sato M, et al. (2005). "The Arabidopsis gene CAD1 controls programmed cell death in the plant immune system and encodes a protein containing a MACPF domain". Plant Cell Physiol. 46 (6): 902–12. doi:10.1093/pcp/pci095. PMID 15799997. 
  10. ^ Oshiro N, Kobayashi C, Iwanaga S, et al. (2004). "A new membrane-attack complex/perforin (MACPF) domain lethal toxin from the nematocyst venom of the Okinawan sea anemone Actineria villosa". Toxicon 43 (2): 225–8. doi:10.1016/j.toxicon.2003.11.017. PMID 15019483. 
  11. ^ Kadota K, Ishino T, Matsuyama T, Chinzei Y, Yuda M (2004). "Essential role of membrane-attack protein in malarial transmission to mosquito host". Proc. Natl. Acad. Sci. U.S.A. 101 (46): 16310–5. doi:10.1073/pnas.0406187101. PMC 524694. PMID 15520375. 
  12. ^ Ishino T, Chinzei Y, Yuda M (2005). "A Plasmodium sporozoite protein with a membrane attack complex domain is required for breaching the liver sinusoidal cell layer prior to hepatocyte infection". Cell. Microbiol. 7 (2): 199–208. doi:10.1111/j.1462-5822.2004.00447.x. PMID 15659064. 
  13. ^ Zheng C, Heintz N, Hatten ME (1996). "CNS gene encoding astrotactin, which supports neuronal migration along glial fibers". Science 272 (5260): 417–9. doi:10.1126/science.272.5260.417. PMID 8602532. 
  14. ^ Haag ES, Sly BJ, Andrews ME, Raff RA (1999). "Apextrin, a novel extracellular protein associated with larval ectoderm evolution in Heliocidaris erythrogramma". Dev. Biol. 211 (1): 77–87. doi:10.1006/dbio.1999.9283. PMID 10373306. 
  15. ^ Martin JR, Raibaud A, Ollo R (1994). "Terminal pattern elements in Drosophila embryo induced by the torso-like protein". Nature 367 (6465): 741–5. doi:10.1038/367741a0. PMID 8107870. 
  16. ^ Ponting CP (1999). "Chlamydial homologues of the MACPF (MAC/perforin) domain". Curr. Biol. 9 (24): R911–3. doi:10.1016/S0960-9822(00)80102-5. PMID 10608922. 
  17. ^ Rossjohn J, Feil SC, McKinstry WJ, Tweten RK, Parker MW (1997). "Structure of a cholesterol-binding, thiol-activated cytolysin and a model of its membrane form". Cell 89 (5): 685–92. doi:10.1016/S0092-8674(00)80251-2. PMID 9182756. 
  18. ^ Tilley SJ, Orlova EV, Gilbert RJ, Andrew PW, Saibil HR (2005). "Structural basis of pore formation by the bacterial toxin pneumolysin". Cell 121 (2): 247–56. doi:10.1016/j.cell.2005.02.033. PMID 15851031. 
  19. ^ Huang Y, Qiao F, Abagyan R, Hazard S, Tomlinson S (2006). "Defining the CD59-C9 binding interaction". J. Biol. Chem. 281 (37): 27398–404. doi:10.1074/jbc.M603690200. PMID 16844690. 
  20. ^ Lockert DH, Kaufman KM, Chang CP, Hüsler T, Sodetz JM, Sims PJ (1995). "Identity of the segment of human complement C8 recognized by complement regulatory protein CD59". J. Biol. Chem. 270 (34): 19723–8. doi:10.1074/jbc.270.8.3483. PMID 7544344. 
  21. ^ Schreck SF, Plumb ME, Platteborze PL, et al. (1998). "Expression and characterization of recombinant subunits of human complement component C8: further analysis of the function of C8 alpha and C8 gamma". J. Immunol. 161 (1): 311–8. PMID 9647238. 
  22. ^ a b Lovelace LL, Chiswell B, Slade DJ, Sodetz JM, Lebioda L (2007). "Crystal structure of complement protein C8gamma in complex with a peptide containing the C8gamma binding site on C8alpha: Implications for C8gamma ligand binding". Molecular Immunology 45 (3): 750–6. doi:10.1016/j.molimm.2007.06.359. PMID 17692377. 
  23. ^ Kieffer B, Driscoll PC, Campbell ID, Willis AC, van der Merwe PA, Davis SJ (1994). "Three-dimensional solution structure of the extracellular region of the complement regulatory protein CD59, a new cell-surface protein domain related to snake venom neurotoxins". Biochemistry 33 (15): 4471–82. doi:10.1021/bi00181a006. PMID 7512825. 
  24. ^ Kira R, Ihara K, Takada H, Gondo K, Hara T (1998). "Nonsense mutation in exon 4 of human complement C9 gene is the major cause of Japanese complement C9 deficiency". Hum. Genet. 102 (6): 605–10. doi:10.1007/s004390050749. PMID 9703418. 
  25. ^ Walport, Mark J. (2001). "Complement. First of two parts". N. Engl. J. Med. 344 (14): 1058–66. doi:10.1056/NEJM200104053441406. PMID 11287977. 
  26. ^ Verbsky JW, Grossman WJ (2006). "Hemophagocytic lymphohistiocytosis: diagnosis, pathophysiology, treatment, and future perspectives". Ann. Med. 38 (1): 20–31. doi:10.1080/07853890500465189. PMID 16448985. 
  27. ^ Wright KO, Messing EM, Reeder JE (2004). "DBCCR1 mediates death in cultured bladder tumor cells". Oncogene 23 (1): 82–90. doi:10.1038/sj.onc.1206642. PMID 14712213. 

External links[edit]

This page is based on a Wikipedia article. The text is available under the Creative Commons Attribution/Share-Alike License.

This tab holds the annotation information that is stored in the Pfam database. As we move to using Wikipedia as our main source of annotation, the contents of this tab will be gradually replaced by the Wikipedia tab.

MAC/Perforin domain Provide feedback

The membrane-attack complex (MAC) of the complement system forms transmembrane channels. These channels disrupt the phospholipid bilayer of target cells, leading to cell lysis and death. A number of proteins participate in the assembly of the MAC. Freshly activated C5b binds to C6 to form a C5b-6 complex, then to C7 forming the C5b-7 complex. The C5b-7 complex binds to C8, which is composed of three chains (alpha, beta, and gamma), thus forming the C5b-8 complex. C5b-8 subsequently binds to C9 and acts as a catalyst in the polymerisation of C9. Active MAC has a subunit composition of C5b-C6-C7-C8-C9{n}. Perforin is a protein found in cytolytic T-cell and killer cells. In the presence of calcium, perforin polymerises into transmembrane tubules and is capable of lysing, non-specifically, a variety of target cells. There are a number of regions of similarity in the sequences of complement components C6, C7, C8-alpha, C8-beta, C9 and perforin. The X-ray crystal structure of a MACPF domain reveals that it shares a common fold with bacterial cholesterol dependent cytolysins (PF01289) such as perfringolysin O. Three key pieces of evidence suggests that MACPF domains and CDCs are homologous: Functional similarity (pore formation), conservation of three glycine residues at a hinge in both families and conservation of a complex core fold [1].

Literature references

  1. Rosado CJ, Buckle AM, Law RH, Butcher RE, Kan WT, Bird CH, Ung K, Browne KA, Baran K, Bashtannyk-Puhalovich TA, Faux NG, Wong W, Porter CJ, Pike RN, Ellisdon AM, Pearce MC, Bottomley SP, Emsley J, Smith AI, Rossjohn J, Hartland EL, Voskoboinik I, Trapani , Science. 2007;317:1548-1551.: A common fold mediates vertebrate defense and bacterial attack. PUBMED:17717151 EPMC:17717151

  2. Hadders MA, Beringer DX, Gros P; , Science. 2007;317:1552-1554.: Structure of C8alpha-MACPF reveals mechanism of membrane attack in complement immune defense. PUBMED:17872444 EPMC:17872444


External database links

This tab holds annotation information from the InterPro database.

InterPro entry IPR020864

The membrane attack complex/perforin (MACPF) domain is conserved in bacteria, fungi, mammals and plants. It was originally identified and named as being common to five complement components (C6, C7, C8-alpha, C8-beta, and C9) and perforin. These molecules perform critical functions in innate and adaptive immunity. The MAC family proteins and perforin are known to participate in lytic pore formation. In response to pathogen infection, a sequential and highly specific interaction between the constituent elements occurs to form transmembrane channels which are known as the membrane-attack complex (MAC).Only a few other MACPF proteins have been characterised and several are thought to form pores for invasion or protection [PUBMED:16900325, PUBMED:17717151, PUBMED:18440555]. Examples are proteins from malarial parasites [PUBMED:15659064], the cytolytic toxins from sea anemones [PUBMED:17368498], and proteins that provide plant immunity [PUBMED:16900325, PUBMED:15799997]. Functionally uncharacterised MACPF proteins are also evident in pathogenic bacteria such as Chlamydia spp [PUBMED:10608922] and Photorhabdus luminescens (Xenorhabdus luminescens) [PUBMED:17717151].

The MACPF domain is commonly found to be associated with other N- and C-terminal domains, such as TSP1 (see PROSITEDOC), LDLRA (see PROSITEDOC), EGF-like (see PROSITEDOC),Sushi/CCP/SCR (see PROSITEDOC), FIMAC or C2 (see PROSITEDOC). They probably control or target MACPF function [PUBMED:17717151, PUBMED:17872444]. The MACPF domain oligomerizes, undergoes conformational change, and is required for lytic activity.

The MACPF domain consists of a central kinked four-stranded antiparallel beta sheet surrounded by alpha helices and beta strands, forming two structural segments. Overall, the MACPF domain has a thin L-shaped appearance. MACPF domains exhibit limited sequence similarity but contain a signature [YW]-G-[TS]-H-[FY]-x(6)-G-G motif [PUBMED:17717151, PUBMED:18440555, PUBMED:17872444].

Some proteins known to contain a MACPF domain are listed below:

  • Vertebrate complement proteins C6 to C9. Complement factors C6 to C9 assemble to form a scaffold, the membrane attack complex (MAC), that permits C9 polymerisation into pores that lyse Gram-negative pathogens [PUBMED:18440555, PUBMED:17872444].
  • Vertebrate perforin. It is delivered by natural killer cells and cytotoxic T lymphocytes and forms oligomeric pores (12 to 18 monomers) in the plasma membrane of either virus-infected or transformed cells.
  • Arabidopsis thaliana (Mouse-ear cress) constitutively activated cell death 1 (CAD1) protein. It is likely to act as a mediator that recognises plant signals for pathogen infection [PUBMED:15799997].
  • Arabidopsis thaliana (Mouse-ear cress) necrotic spotted lesions 1 (NSL1) protein [PUBMED:16900325].
  • Venomous sea anemone Phyllodiscus semoni (Night anemone) toxins PsTX-60A and PsTX-60B [PUBMED:17368498].
  • Venomous sea anemone Actineria villosa (Okinawan sea anemone) toxin AvTX-60A [PUBMED:17368498].
  • Plasmodium sporozoite microneme protein essential for cell traversal 2 (SPECT2). It is essential for the membrane-wounding activity of the sporozoite and is involved in its traversal of the sinusoidal cell layer prior to hepatocyte-infection [PUBMED:15659064].
  • P. luminescens Plu-MACPF. Although nonlytic, it was shown to bind to cell membranes [PUBMED:17717151].
  • Chlamydial putative uncharacterised protein CT153 [PUBMED:10608922].

Domain organisation

Below is a listing of the unique domain organisations or architectures in which this domain is found. More...

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Pfam Clan

This family is a member of clan CDC (CL0293), which has the following description:

This superfamily includes the MACPF domain as well as the Cholesterol-dependent cytolysins [1].

The clan contains the following 2 members:

MACPF Thiol_cytolysin

Alignments

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(1344)
Representative proteomes NCBI
(1199)
Meta
(5)
RP15
(245)
RP35
(380)
RP55
(547)
RP75
(771)
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  Seed
(69)
Full
(1344)
Representative proteomes NCBI
(1199)
Meta
(5)
RP15
(245)
RP35
(380)
RP55
(547)
RP75
(771)
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Pfam alignments:

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Trees

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Curation and family details

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Seed source: SMART
Previous IDs: none
Type: Domain
Author: SMART
Number in seed: 69
Number in full: 1344
Average length of the domain: 197.40 aa
Average identity of full alignment: 16 %
Average coverage of the sequence by the domain: 29.28 %

HMM information View help on HMM parameters

HMM build commands:
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 23193494 -E 1000 --cpu 4 HMM pfamseq
Model details:
Parameter Sequence Domain
Gathering cut-off 20.7 20.7
Trusted cut-off 20.8 20.7
Noise cut-off 20.4 20.6
Model length: 212
Family (HMM) version: 14
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Species distribution

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Structures

For those sequences which have a structure in the Protein DataBank, we use the mapping between UniProt, PDB and Pfam coordinate systems from the PDBe group, to allow us to map Pfam domains onto UniProt sequences and three-dimensional protein structures. The table below shows the structures on which the MACPF domain has been found. There are 9 instances of this domain found in the PDB. Note that there may be multiple copies of the domain in a single PDB structure, since many structures contain multiple copies of the same protein seqence.

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