IMMT

IMMT
Identifiers
Aliases	IMMT, HMP, MINOS2, P87, P87/89, P89, PIG52, Mic60, PIG4, inner membrane mitochondrial protein, MICOS60, mitofilin
External IDs	OMIM: 600378; MGI: 1923864; HomoloGene: 38234; GeneCards: IMMT; OMA:IMMT - orthologs
Gene location (Human) Chr. Chromosome 2 (human)[1] Band 2p11.2|2 Start 86,143,932 bp[1] End 86,195,472 bp[1]
Gene location (Mouse) Chr. Chromosome 6 (mouse)[2] Band 6|6 C1 Start 71,808,315 bp[2] End 71,854,372 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in left ventricle gastrocnemius muscle apex of heart right auricle biceps brachii right ventricle Skeletal muscle tissue of biceps brachii gonad right adrenal cortex body of tongue Top expressed in myocardium of ventricle tail of embryo genital tubercle right kidney right ventricle cardiac muscles soleus muscle muscle of thigh digastric muscle brown adipose tissue More reference expression data BioGPS More reference expression data
Gene ontology Molecular function protein binding RNA binding Cellular component integral component of membrane mitochondrial inner membrane myelin sheath MICOS complex membrane mitochondrion Biological process cristae formation mitochondrial calcium ion homeostasis Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 10989 76614 Ensembl ENSG00000132305 ENSMUSG00000052337 UniProt Q16891 Q8CAQ8 RefSeq (mRNA) NM_001100169 NM_001100170 NM_006839 NM_001253681 NM_001253686 NM_001253687 NM_001253688 NM_001253689 NM_029673 NM_001362134 NM_001362136 NM_001362137 NM_001362138 RefSeq (protein) NP_001093639 NP_001093640 NP_006830 NP_001240610 NP_001240615 NP_001240616 NP_001240617 NP_001240618 NP_083949 NP_001349063 NP_001349065 NP_001349066 NP_001349067 Location (UCSC) Chr 2: 86.14 – 86.2 Mb Chr 6: 71.81 – 71.85 Mb PubMed search [3] [4]
Wikidata
View/Edit Human View/Edit Mouse

Mitochondrial inner membrane protein is a protein that in humans is encoded by the IMMT gene.^[5][6][7])

IMMT encodes an inner mitochondrial membrane (IMM) protein in the nucleus. It is posttranslational transported to the IMM. Mic60/Mitofilin (encoded by the IMMT gene) is a core subunit of the MICOS-complex, directly located next to cristae junctions (CJ). Human Mic60 exists in two isoforms of different size, anchored to the IMM via its N-terminus, while most of the protein is located to the inner mitochondrial space (IMS).

Function

Mic60 is evolutionary one of the oldest MICOS subunits as homologous were found in anaerobic prokaryotes. It is mainly present in two isoforms (ca. 88 and 90 kDa). In the brain, four isoforms are known, which differ in their isoelectric point due to different post-translational modifications. The amino terminus of Mic60 is anchored in the IM, while most of the protein is extended to the IMS. C-terminal Mic60 has a conserved mitofilin domain which is crucial for building the MICOS-complex. A central coiled-coil domain is required to enable protein-protein interactions.

Interactions

Mic60 indirectly interacts with all known MICOS-complex and SAM complex components. It directly interacts with Mic25, Mic19 and SAM50. Together with Mic25 and Mic19, Mic60 forms the Mic60-Mic19-Mic25 subcomplex. This subcomplex, especially Mic60, is crucial for the physical contact between the IMM and the outer mitochondrial membrane (OMM) via its interaction with SAM50. Mic60 also interacts with the translocase of the OMM (TOM) and the translocase of the IMM (TIM) to ensure the localization of Mic60 near to CJs. Through its interaction with TOM and TIM, Mic60 additionally influences the import of precursor proteins.

Localisation/Import

Mic60 is translated in the cytosol and translocated into the IMS via TOMM40. TIMM23 transports Mic60 into the IM, where a mitochondrial processing peptidase (MPP) cleaves of the N-terminal mitochondrial targeting signal (MTS). Mic60 is anchored in the IMM through its transmembrane (TM) domain.

Interactions

IMMT has been shown to interact with BAT2.^[8])

References

Further reading