Maurer's cleft

GO:0020036 · Membrane organelle · Membrane bounded organelle · Proposed

A disk-like structure that appears at the periphery of a red blood cell infected by an apicomplexan parasite, characterized by a translucent lumen and an electron-dense coat of variable thickness; often appears to be tethered to the host cell membrane by fibrous connections with the erythrocyte cytoskeleton. [GO:0020036]

UniProt location names: UniProt Consortium, CC BY 4.0. Reference label and route sources.

Components

Component	Type	Part of / acts on	Grounding	Essential	Role
Maurer's cleft membrane	Lipid	part of	Reviewed label only (reviewed name; no accession asserted)	ESSENTIAL	Parasite-derived membrane boundary of the flattened cleft in the infected red-blood-cell cytoplasm. `DOI:10.1016/j.ijpara.2005.10.001` Lanzer et al. 2006 reviewed Maurer's clefts as flattened membranous organelles induced by Plasmodium falciparum in infected erythrocytes. `DOI:10.1016/S0166-6851(00)00301-7` Blisnick et al. 2000 localized the integral membrane protein PfSBP1 to Maurer's clefts in P. falciparum-infected erythrocytes.
Maurer's cleft resident proteins	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	UNKNOWN	Plasmodium-exported proteins that reside at Maurer's clefts and participate in trafficking or organizing virulence cargo in infected erythrocytes. `DOI:10.1111/j.1365-2958.2008.06235.x` Spycher et al. 2008 studied the Maurer's cleft protein MAHRP1 and found that MAHRP1 loss prevents PfEMP1 presentation on the infected red-blood-cell surface. `DOI:10.1083/jcb.200509122` Cooke et al. 2006 disrupted skeleton-binding protein 1 and showed that PfEMP1 still reached Maurer's clefts but was not presented on the infected red-blood-cell surface.
skeleton-binding protein 1	Protein	part of	Reviewed label only (reviewed name; no accession asserted)	UNKNOWN	Integral Maurer's cleft membrane protein implicated in anchoring clefts to the erythrocyte skeleton and required for efficient PfEMP1 surface display in P. falciparum-infected erythrocytes. `DOI:10.1016/S0166-6851(00)00301-7` Blisnick et al. 2000 characterized PfSBP1 as an integral Maurer's cleft membrane protein associated with the erythrocyte skeleton. `DOI:10.1083/jcb.200509122` Cooke et al. 2006 found that deleting SBP1 blocked PfEMP1 expression on the infected red-blood-cell surface.

Taxonomic distribution

NCBITaxon:5833 Plasmodium falciparum — COMMON: P. falciparum asexual blood-stage parasites induce Maurer's clefts in the cytoplasm of infected human erythrocytes. [DOI:10.1016/j.ijpara.2005.10.001]

Canonical examples

NCBITaxon:5833 Plasmodium falciparum — Human malaria parasite in which Maurer's cleft resident proteins such as SBP1 and MAHRP1 have been tested genetically for PfEMP1 trafficking. [DOI:10.1083/jcb.200509122]

Functions

erythrocyte surface virulence-protein trafficking — Maurer's clefts act as intermediate compartments that help traffic parasite virulence proteins, including PfEMP1, toward the infected erythrocyte surface.
- DOI:10.1016/j.ijpara.2005.10.001 Lanzer et al. 2006 reviewed Maurer's cleft morphology and protein-trafficking roles in P. falciparum-infected erythrocytes.
- DOI:10.1111/j.1365-2958.2008.06235.x Spycher et al. 2008 found that MAHRP1 loss depletes PfEMP1 from Maurer's clefts and prevents PfEMP1 surface presentation.

Mechanism graphs

Maurer's cleft proteins support infected-cell surface cargo display (FUNCTION)

The Maurer's cleft membrane houses resident Plasmodium proteins, including SBP1, that contribute to delivery of PfEMP1 toward the infected erythrocyte surface.

Subject	Predicate	Object	Evidence
Maurer's cleft membrane	bounds	Maurer's cleft	`DOI:10.1016/j.ijpara.2005.10.001` Lanzer et al. 2006 reviewed Maurer's clefts as membranous organelles in P. falciparum-infected erythrocytes.
skeleton-binding protein 1	localizes to	Maurer's cleft membrane	`DOI:10.1016/S0166-6851(00)00301-7` Blisnick et al. 2000 localized PfSBP1 to the Maurer's cleft membrane.
Maurer's cleft resident proteins	localize to	Maurer's cleft	`DOI:10.1111/j.1365-2958.2008.06235.x` Spycher et al. 2008 localized MAHRP1 to Maurer's clefts and tested its role in PfEMP1 trafficking.
Maurer's cleft	supports	PfEMP1 trafficking	`DOI:10.1083/jcb.200509122` Cooke et al. 2006 found that in SBP1 knockout parasites PfEMP1 still reaches Maurer's clefts but no longer appears on the infected-cell surface.
PfEMP1 trafficking	delivers cargo to	infected erythrocyte surface	`DOI:10.1111/j.1365-2958.2008.06235.x` Spycher et al. 2008 showed that MAHRP1 deletion depletes PfEMP1 from Maurer's clefts and blocks PfEMP1 surface presentation.

Discussions

INTERPRETATION (RESOLVED): Model Maurer's clefts as parasite-derived structures inside infected erythrocytes rather than as a conserved host red-blood-cell organelle. Maurer's clefts are induced by malaria parasites in the host erythrocyte cytoplasm and are populated by parasite-exported proteins; this record therefore uses Plasmodium falciparum as the canonical taxon and avoids treating the clefts as normal erythrocyte organelles.
CURATION_TODO (OPEN): Resolve exact source-neutral families for SBP1, MAHRP1, and other Maurer's cleft resident protein classes. The first record curates SBP1 and MAHRP1 from P. falciparum localization and knockout evidence but does not assign broad domain-family CURIEs to exact Maurer's cleft resident protein classes.

Evidence

GO:0020036 Gene Ontology cellular-component term for Maurer's cleft.
GO:0043231 Gene Ontology cellular-component parent for intracellular membrane-bounded organelles.
DOI:10.1016/j.ijpara.2005.10.001 Lanzer et al. 2006, Maurer's clefts: a novel multi-functional organelle in the cytoplasm of Plasmodium falciparum-infected erythrocytes, International Journal for Parasitology.
DOI:10.1016/S0166-6851(00)00301-7 Blisnick et al. 2000, Pfsbp1, a Maurer's cleft Plasmodium falciparum protein, is associated with the erythrocyte skeleton, Molecular and Biochemical Parasitology.
DOI:10.1083/jcb.200509122 Cooke et al. 2006, A Maurer's cleft-associated protein is essential for expression of the major malaria virulence antigen on the surface of infected red blood cells, Journal of Cell Biology.
DOI:10.1111/j.1365-2958.2008.06235.x Spycher et al. 2008, The Maurer's cleft protein MAHRP1 is essential for trafficking of PfEMP1 to the surface of Plasmodium falciparum-infected erythrocytes, Molecular Microbiology.

Curation history

2026-09-22T07:33:56Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-22T07:35:19Z codex · EXPANDED_RECORD — Added membrane and resident-protein components, P. falciparum taxonomic scope, a PfEMP1 trafficking function, DOI evidence, a nonmechanistic Maurer's-cleft trafficking graph, and discussions for host-cell boundary and protein-family grounding.

Source: data/structures/membrane_organelle/maurer_s_cleft.yaml