ApiLoc - A database of published protein sub-cellular localisation in Apicomplexa

version 3 (curated until May 28, 2011)

A novel family of Apicomplexan glideosome-associated proteins with an inner membrane-anchoring role.

Bullen, H. E., Tonkin, C. J., O'Donnell, R. A., Tham, W. H., Papenfuss, A. T., Gould, S., Cowman, A. F., Crabb, B. S., Gilson, P. R. (2009 Sep 11, J Biol Chem)

The phylum Apicomplexa are a group of obligate intracellular parasites responsible for a wide range of important diseases. Central to the lifecycle of these unicellular parasites is their ability to migrate through animal tissue and invade target host cells. Apicomplexan movement is generated by a unique system of gliding motility in which substrate adhesins and invasion-related proteins are pulled across the plasma membrane by an underlying actin-myosin motor. The myosins of this motor are inserted into a dual membrane layer called the inner membrane complex (IMC) that is sandwiched between the plasma membrane and an underlying cytoskeletal basket. Central to our understanding of gliding motility is the characterization of proteins residing within the IMC, but to date only a few proteins are known. We report here a novel family of six-pass transmembrane proteins, termed the GAPM family, which are highly conserved and specific to Apicomplexa. In Plasmodium falciparum and Toxoplasma gondii the GAPMs localize to the IMC where they form highly SDS-resistant oligomeric complexes. The GAPMs co-purify with the cytoskeletal alveolin proteins and also to some degree with the actin-myosin motor itself. Hence, these proteins are strong candidates for an IMC-anchoring role, either directly or indirectly tethering the motor to the cytoskeleton.

PubMed: 19561073, full text

Localisation information

MAL13P1.130 (GAPM1) glideosome associated protein with multiple membrane spans 1

Experimental localisation: inner membrane complex during early schizont, not parasite plasma membrane during early schizont
  • Species: Plasmodium falciparum
  • Quote inferring localisation: "The localisation pattern of PfGAPM1-HA and PfGAPM3-HA was indistinguishable from that of PfGAP45 and markedly distinct from that of known plasma membrane protein MSP1 (Fig. 2A, Fig. S4). Additionally, live fluorescence microscopy of PfGAPM1-GFP and PfGAPM2- GFP transgenic schizonts demonstrated an identical IMC expression pattern to that of PfGAPM1-HA and PfGAPM3-HA throughout schizogony and a developmental series of images is shown in Figure S3. "
  • Microscopy type: Light
  • Microscopy method: HA tag, GFP tag
  • Strain: 3D7
  • Gene model mapping comments: Blast from CAD52385, taken directly from publication
  • Localisation record: IMC and not surface during immature schizont

PFD1110w (GAPM2) glideosome associated protein with multiple membrane spans 2

Experimental localisation: inner membrane complex during ring, inner membrane complex during trophozoite, inner membrane complex during schizont
  • Species: Plasmodium falciparum
  • Quote inferring localisation: "Additionally, live fluorescence microscopy of PfGAPM1-GFP and PfGAPM2- GFP transgenic schizonts demonstrated an identical IMC expression pattern to that of PfGAPM1-HA and PfGAPM3-HA throughout schizogony and a developmental series of images is shown in Figure S3. "
  • Microscopy type: Light
  • Microscopy method: GFP tag
  • Strain: 3D7
  • Gene model mapping comments: Blast from CAD49269, taken directly from publication
  • Localisation record: IMC during blood stages

PF14_0065 (GAPM3) glideosome associated protein with multiple membrane spans 3, putative

Experimental localisation: inner membrane complex during schizont, not parasite plasma membrane during schizont
  • Species: Plasmodium falciparum
  • Quote inferring localisation: "The localisation pattern of PfGAPM1-HA and PfGAPM3-HA was indistinguishable from that of PfGAP45 and markedly distinct from that of known plasma membrane protein MSP1 (Fig. 2A, Fig. S4)."
  • Microscopy type: Light
  • Microscopy method: HA tag
  • Strain: 3D7
  • Gene model mapping comments: Blast from AAN36677, taken directly from publication
  • Localisation record: IMC and not surface during schizont

PFL1090w (GAP45) glideosome-associated protein 45

Experimental localisation: inner membrane complex during ring, inner membrane complex during trophozoite, inner membrane complex during schizont
  • Species: Plasmodium falciparum
  • Quote inferring localisation: ""
  • Microscopy type: Light
  • Microscopy method: polyclonal antibody directly to protein
  • Strain: 3D7
  • Gene model mapping comments: inferred from another publication
  • Localisation record: IMC during blood stages

PFI1475w (MSP1, MSP-1, msp1 unprocessed, msp1, Msp-1 19, MSP1 19) merozoite surface protein 1

Experimental localisation: parasite plasma membrane during ring, parasite plasma membrane during trophozoite, parasite plasma membrane during schizont
  • Species: Plasmodium falciparum
  • Quote inferring localisation: ""
  • Microscopy type: Light
  • Microscopy method: polyclonal antibody directly to protein
  • Strain: 3D7
  • Gene model mapping comments: inferred from another publication
  • Localisation record: PPM during blood stages

TGME49_002500 (GAPM1a) hypothetical protein

Experimental localisation: inner membrane complex during extracellular tachyzoite
  • Species: Toxoplasma gondii
  • Quote inferring localisation: "Upon fluorescence microscopy, treated parasites exhibited markedly swollen outer membranes whilst TgGAPM-ChFP-HA labelling was only apparent in the normal crescent shape of the parasite confirming IMC localisation (Fig. 2B). "
  • Microscopy type: Light
  • Microscopy method: cherry tag
  • Strain: RH
  • Gene model mapping comments: Blast from EEB00395
  • Localisation record: IMC during extracellular tachyzoite

TGME49_006690 (GAPM2b) hypothetical protein, conserved

Experimental localisation: inner membrane complex during extracellular tachyzoite
  • Species: Toxoplasma gondii
  • Quote inferring localisation: "Upon fluorescence microscopy, treated parasites exhibited markedly swollen outer membranes whilst TgGAPM-ChFP-HA labelling was only apparent in the normal crescent shape of the parasite confirming IMC localisation (Fig. 2B). "
  • Microscopy type: Light
  • Microscopy method: cherry tag
  • Strain: RH
  • Gene model mapping comments: Blast from EEB00710
  • Localisation record: IMC during extracellular tachyzoite

TGME49_071970 (GAPM3) hypothetical protein

Experimental localisation: inner membrane complex during extracellular tachyzoite
  • Species: Toxoplasma gondii
  • Quote inferring localisation: "Upon fluorescence microscopy, treated parasites exhibited markedly swollen outer membranes whilst TgGAPM-ChFP-HA labelling was only apparent in the normal crescent shape of the parasite confirming IMC localisation (Fig. 2B). "
  • Microscopy type: Light
  • Microscopy method: cherry tag
  • Strain: RH
  • Gene model mapping comments: Blast from EEA98700
  • Localisation record: IMC during extracellular tachyzoite

TGME49_033460 (SAG1, SRS29B, P30/SAG1, BSR4, P30) SRS29B (= SAG1, P30)

Experimental localisation: parasite plasma membrane during extracellular tachyzoite
  • Species: Toxoplasma gondii
  • Quote inferring localisation: "Treated transgenic parasites were fixed and labelled with antibodies specific to the parasite plasma membrane (SAG1) and the TgGAPM- ChFP-HA fusion protein (anti-HA). "
  • Microscopy type: Light
  • Microscopy method: cherry tag
  • Strain: RH
  • Gene model mapping comments: inferred from another publication
  • Localisation record: surface during extracellular tachyzoite