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IMMT

From Wikipedia, the free encyclopedia
IMMT
Identifiers
AliasesIMMT, HMP, MINOS2, P87, P87/89, P89, PIG52, Mic60, PIG4, inner membrane mitochondrial protein, MICOS60, mitofilin
External IDsOMIM: 600378; MGI: 1923864; HomoloGene: 38234; GeneCards: IMMT; OMA:IMMT - orthologs
Orthologs
SpeciesHumanMouse
Entrez
Ensembl
UniProt
RefSeq (mRNA)

NM_001100169
NM_001100170
NM_006839

RefSeq (protein)

NP_001093639
NP_001093640
NP_006830

Location (UCSC)Chr 2: 86.14 – 86.2 MbChr 6: 71.81 – 71.85 Mb
PubMed search[3][4]
Wikidata
View/Edit HumanView/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

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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

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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

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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

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

References

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  1. ^ a b c GRCh38: Ensembl release 89: ENSG00000132305Ensembl, May 2017
  2. ^ a b c GRCm38: Ensembl release 89: ENSMUSG00000052337Ensembl, May 2017
  3. ^ "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  4. ^ "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  5. ^ Gieffers C, Korioth F, Heimann P, Ungermann C, Frey J (May 1997). "Mitofilin is a transmembrane protein of the inner mitochondrial membrane expressed as two isoforms". Experimental Cell Research. 232 (2): 395–399. doi:10.1006/excr.1997.3539. PMID 9168817.
  6. ^ Icho T, Ikeda T, Matsumoto Y, Hanaoka F, Kaji K, Tsuchida N (July 1994). "A novel human gene that is preferentially transcribed in heart muscle". Gene. 144 (2): 301–306. doi:10.1016/0378-1119(94)90394-8. PMID 8039717.
  7. ^ "Entrez Gene: IMMT inner membrane protein, mitochondrial (mitofilin)".
  8. ^ Lehner B, Semple JI, Brown SE, Counsell D, Campbell RD, Sanderson CM (January 2004). "Analysis of a high-throughput yeast two-hybrid system and its use to predict the function of intracellular proteins encoded within the human MHC class III region". Genomics. 83 (1): 153–167. doi:10.1016/S0888-7543(03)00235-0. PMID 14667819.

Further reading

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