During host cell infection by tachyzoites, required for tethering the parasitophorous vacuole to the host mitochondria (PubMed:26920761, PubMed:24781109, PubMed:28567444, PubMed:33723040, PubMed:35025629, PubMed:29505111). This process, known as host mitochondrial association (HMA), induces the formation of SPOTs (structures positive for outer mitochondrial membrane (OMM)), a cellular response to OMM stress, which leads to the constitutive shedding of OMM vesicles containing proteins such as mitofusins MFN1 and MFN2, which normally restrict parasite growth (PubMed:35025629). Specifically, binds to the host OMM import receptor TOMM70 to interact with SAMM50, a component of host mitochondrial intermembrane space bridging (MIB) complex (PubMed:28567444, PubMed:33723040, PubMed:35025629). By targeting SAMM50, induces the disassembly of the MIB complex, thereby promoting the formation of SPOTs (PubMed:35025629). Inhibits host TOMM70 import activity (PubMed:35025629). Plays a role in the modulation of the host innate immune response to parasite infection (PubMed:24781109, PubMed:30333181). Associates with the host mitochondrial intermembrane space bridging (MIB) complex (PubMed:28567444). Interacts with host import receptor TOMM70; the interaction impairs TOMM70 import activity and enables the parasite to associate with the host mitochondria and then with SAMM50; the interaction is likely to be indirect (PubMed:33723040, PubMed:35025629). Interacts with host MIB complex component SAMM50; the interaction requires prior binding to host import receptor TOMM70 and is likely to be indirect (PubMed:28567444, PubMed:29505111). Localizes to dense granules (PubMed:24781109). Localizes at the interface between the parasitophorous vacuole and the host outer mitochondrial membrane (PubMed:26920761, PubMed:24781109). Expressed in tachyzoites (at protein level). The proline-rich region is not required for host mitochondrial association (HMA). Phosphorylated. The MAF1 locus encodes multiple tandemly duplicated paralogs that vary in expression, sequence and copy number across T.gondii strains (PubMed:26920761, PubMed:24781109). For instance, type I strain GT1 has 6 copies, type I strain RH has 4 copies, type II strains ME49 and PRU have 4 copies, type III strain VEG has 4 copies and type III strain CTG has only 2 copies (PubMed:26920761). The paralogs are classified into two groups, a and b and have probably arisen from the neofunctionalization of an ancestral MAF1 a gene (PubMed:26920761). They are characterized by the presence or absence of a repetitive stretch of 4 to 7 prolines followed by a serine (P(4:7)S), as well as differences in the amino acids surrounding the proline motif (PubMed:26920761). This motif is either completely missing (a and b0 paralogs) or repeated up to six times (b paralogs) (PubMed:26920761). cross the strains, transcript levels for the a paralogs are similar, however, in type II strain ME49, transcript levels for the b paralogs are low and no paralog MAF1 b1 protein is produced (PubMed:26920761, PubMed:24781109). Paralogs differ in their ability to mediate host mitochondrial association (HMA), but also in their ability to confer a selective advantage during infection in a mouse model (PubMed:26920761, PubMed:24781109, PubMed:29505111). Tachyzoites from type I and III strains associate with host mitochondria (HMA(+)), while tachyzoites from type II strains, such as ME49, do not associate with host mitochondria (HMA(-)) due to a lack of MAF1 b1 expression (PubMed:26920761, PubMed:24781109). Deletion of the whole MAF1 locus (which includes all a and b paralogs) causes a loss in tachyzoite parasitophorous vacuole association with host mitochondria (HMA) upon host infection without causing any significant growth defect to the parasite (PubMed:24781109, PubMed:28567444). Prevents the formation of SPOTs (structures positive for outer mitochondrial membrane (OMM)) (PubMed:35025629). Partially impairs the reduction in mitochondrial protein abundance caused by infection; specifically, prevents the loss of MFN1, MFN2 and MIRO2 proteins (PubMed:35025629). Intraperitoneal infection of C57BL/6J mice with knockout tachyzoites results in similar mouse lethality and parasite burden compared to infection with wild type parasite (PubMed:24781109). However, levels of several cytokines and chemokines, including IL4 and CCL11/eotaxin from mouse peritoneal exudate cells (PECs) is reduced (PubMed:24781109).