ATP-dependent metalloprotease YME1L1 is an

enzyme An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...

that in humans is encoded by the ''YME1L1''

gene In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...

. YME1L1 belongs to the AAA family of

ATPases ATPases (, Adenosine 5'-TriPhosphatase, adenylpyrophosphatase, ATP monophosphatase, triphosphatase, ATP hydrolase, adenosine triphosphatase) are a class of enzymes that catalysis, catalyze the decomposition of adenosine triphosphate, ATP into a ...

and mainly functions in the maintenance of mitochondrial morphology.

Mutations In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA. Mutations result from errors during DNA or viral replication, mitosi ...

in this gene would cause infantile-onset mitochondriopathy.

Structure

Gene

The ''YME1L1'' gene is located at

chromosome 10 Chromosome 10 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 10 spans about 134 million base pairs (the building material of DNA) and represents between 4 and 4.5 percent of the tota ...

p14, consisting of 20

exons An exon is any part of a gene that will form a part of the final mature RNA produced by that gene after introns have been removed by RNA splicing. The term ''exon'' refers to both the DNA sequence within a gene and to the corresponding sequence i ...

. Two transcript variants encoding different

isoforms A protein isoform, or "protein variant", is a member of a set of highly similar proteins that originate from a single gene and are the result of genetic differences. While many perform the same or similar biological roles, some isoforms have uniqu ...

have been found for this gene.

Protein

YME1L1 consists of 716

amino acids Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although over 500 amino acids exist in nature, by far the most important are the Proteinogenic amino acid, 22 α-amino acids incorporated into p ...

and is highly similar to all mitochondrial AAA proteases and in particular to

yeast Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom (biology), kingdom. The first yeast originated hundreds of millions of years ago, and at least 1,500 species are currently recognized. They are est ...

Yme1p. Three different domains are identified via sequence analysis, including an AAA consensus sequence between amino acids 317 and 502, an ATP/GTP binding motif, and a HEXXH motif typical of a

zinc Zinc is a chemical element; it has symbol Zn and atomic number 30. It is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodic tabl ...

-dependent binding

domain A domain is a geographic area controlled by a single person or organization. Domain may also refer to: Law and human geography * Demesne, in English common law and other Medieval European contexts, lands directly managed by their holder rather ...

Function

YME1L1 is embedded in the

inner mitochondrial membrane The inner mitochondrial membrane (IMM) is the mitochondrial membrane which separates the mitochondrial matrix from the intermembrane space. Structure The structure of the inner mitochondrial membrane is extensively folded and compartmentalized. T ...

and is more abundant in tissues with a high content of mitochondria such as human adult heart,

skeletal muscle Skeletal muscle (commonly referred to as muscle) is one of the three types of vertebrate muscle tissue, the others being cardiac muscle and smooth muscle. They are part of the somatic nervous system, voluntary muscular system and typically are a ...

, and

pancreas The pancreas (plural pancreases, or pancreata) is an Organ (anatomy), organ of the Digestion, digestive system and endocrine system of vertebrates. In humans, it is located in the abdominal cavity, abdomen behind the stomach and functions as a ...

RNA Ribonucleic acid (RNA) is a polymeric molecule that is essential for most biological functions, either by performing the function itself (non-coding RNA) or by forming a template for the production of proteins (messenger RNA). RNA and deoxyrib ...

. YME1L1 is a member of the AAA family of ATPases and has an important role for the maintenance of mitochondrial morphology. Its mature form assembles into a homo-oligomeric complex within the inner mitochondrial membrane (IM). It degrades both intermembrane space and IM proteins, including lipid transfer proteins, components of protein translocases of the IM, and the dynamin-like GTPase optic atrophy 1 (

OPA1 Dynamin-like 120 kDa protein, mitochondrial is a protein that in humans is encoded by the ''OPA1'' gene. This protein regulates mitochondrial fusion and cristae structure in the inner mitochondrial membrane (IMM) and contributes to ATP synthesis ...

) Loss of YME1L1 accelerates OMA1-dependent long-form OPA1 cleavage, resulting in short-form OPA1 accumulation, increased

mitochondrial fission Mitochondrial fission is the process by which mitochondria divide or segregate into two separate mitochondrial organelles. Mitochondrial fission is counteracted by mitochondrial fusion, where two mitochondria fuse together to form a larger one. Fu ...

, and mitochondrial network fragmentation. It's also reported that YME1L1 controls the accumulation of

respiratory chain An electron transport chain (ETC) is a series of protein complexes and other molecules which transfer electrons from electron donors to electron acceptors via redox reactions (both reduction and oxidation occurring simultaneously) and couples this ...

subunits and is required for

apoptotic Apoptosis (from ) is a form of programmed cell death that occurs in multicellular organisms and in some eukaryotic, single-celled microorganisms such as yeast. Biochemical events lead to characteristic cell changes ( morphology) and death. These ...

resistance, cristae morphogenesis, and

cell proliferation Cell proliferation is the process by which ''a cell grows and divides to produce two daughter cells''. Cell proliferation leads to an exponential increase in cell number and is therefore a rapid mechanism of tissue growth. Cell proliferation ...

Clinical significance

homozygous Zygosity (the noun, zygote, is from the Greek "yoked," from "yoke") () is the degree to which both copies of a chromosome or gene have the same genetic sequence. In other words, it is the degree of similarity of the alleles in an organism. Mos ...

mutation in the YME1L1 gene would cause infantile-onset mitochondriopathy, with severe intellectual disability, muscular impairments, and optic nerve

atrophy Atrophy is the partial or complete wasting away of a part of the body. Causes of atrophy include mutations (which can destroy the gene to build up the organ), malnutrition, poor nourishment, poor circulatory system, circulation, loss of hormone, ...

. The

missense mutation In genetics, a missense mutation is a point mutation in which a single nucleotide change results in a codon that codes for a different amino acid. It is a type of nonsynonymous substitution. Missense mutations change amino acids, which in turn alt ...

affects the MPP processing site and impairs YME1L1 maturation, leading to its rapid degradation, and also leads to a proliferation defect, abnormal OPA1 processing and mitochondrial fragmentation.

Interactions

*OPA1 *OMA1