60S ribosomal protein L38 is a

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, res ...

that in humans is encoded by the ''RPL38''

gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ...

Gene

The human RPL38 gene resides on the long arm of

chromosome 17 Chromosome 17 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 17 spans more than 83 million base pairs (the building material of DNA) and represents between 2.5 and 3% of the total D ...

at 17q25.1. It consists of five exons spread out over a distance of 6223 bp. The 213 nucleotide

open reading frame In molecular biology, open reading frames (ORFs) are defined as spans of DNA sequence between the start and stop codons. Usually, this is considered within a studied region of a prokaryotic DNA sequence, where only one of the six possible readin ...

encodes a 70 amino acid

. Alternative splice variants have been identified, both encoding the same protein. As is typical for genes encoding ribosomal proteins, there are multiple processed pseudogenes of this gene dispersed through the genome, including one located in the promoter region of the

angiotensin II receptor type 1 Angiotensin II receptor type 1 (AT1) is the best characterized angiotensin receptor. It is encoded in humans by the ''AGTR1'' gene. AT1 has vasopressor effects and regulates aldosterone secretion. It is an important effector controlling blood pre ...

gene.

Function

Ribosomes, the organelles that catalyze protein synthesis, consist of a small 40S subunit and a large 60S subunit. Together these subunits are composed of 4 RNA species and approximately 80 structurally distinct proteins. This gene encodes a ribosomal protein that is a component of the 60S subunit. The protein belongs to the L38E family of ribosomal proteins. It is located in the

cytoplasm In cell biology, the cytoplasm is all of the material within a eukaryotic cell, enclosed by the cell membrane, except for the cell nucleus. The material inside the nucleus and contained within the nuclear membrane is termed the nucleoplasm. ...

Genetics

An ~18kbp deletion, encompassing the entire ''Rpl38''

locus Locus (plural loci) is Latin for "place". It may refer to: Entertainment * Locus (comics), a Marvel Comics mutant villainess, a member of the Mutant Liberation Front * ''Locus'' (magazine), science fiction and fantasy magazine ** ''Locus Award' ...

underlies the

phenotype In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology or physical form and structure, its developmental processes, its biochemical and physiological pr ...

in the Tail-short (''Ts'') mutant mouse. In

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. Mo ...

state, ''Ts'' mice die at around 3–4 days of gestation. ''Ts/+'' heterozygous embryos undergo an

anemia Anemia or anaemia (British English) is a blood disorder in which the blood has a reduced ability to carry oxygen due to a lower than normal number of red blood cells, or a reduction in the amount of hemoglobin. When anemia comes on slowly, t ...

and develop skeletal malformations. During the perinatal period ~30% of the heterozygotes die. The surviving heterozygous ''Ts'' exhibit great variations of shortened, kinked and otherwise malformed tails. They also weigh less than their wild-type littermates but have otherwise a normal life span. Additionally, ''Ts'' mice develop a

conductive hearing loss Conductive hearing loss (CHL) occurs when there is a problem transferring sound waves anywhere along the pathway through the outer ear, tympanic membrane (eardrum), or middle ear (ossicles). If a conductive hearing loss occurs in conjunction with ...

shortly after the onset of hearing at around 3–4 weeks of age. The hearing loss is the result of ectopic

ossification Ossification (also called osteogenesis or bone mineralization) in bone remodeling is the process of laying down new bone material by cells named osteoblasts. It is synonymous with bone tissue formation. There are two processes resulting in ...

along the round window ridge at the outside of the

cochlea The cochlea is the part of the inner ear involved in hearing. It is a spiral-shaped cavity in the bony labyrinth, in humans making 2.75 turns around its axis, the modiolus. A core component of the cochlea is the Organ of Corti, the sensory or ...

, massive deposition of cholesterol crystals in the middle ear cavity, an enlarged Eustachian tube and a chronic

otitis media Otitis media is a group of inflammatory diseases of the middle ear. One of the two main types is acute otitis media (AOM), an infection of rapid onset that usually presents with ear pain. In young children this may result in pulling at the ear, ...

with effusion. In

Drosophila melanogaster ''Drosophila melanogaster'' is a species of fly (the taxonomic order Diptera) in the family Drosophilidae. The species is often referred to as the fruit fly or lesser fruit fly, or less commonly the " vinegar fly" or "pomace fly". Starting with ...

, loss-of-function alleles of RPL38, cause embryonic lethality in homozygotes and protracted growth and shortened bristles in heterozygotes. Due to the haplo-insufficient nature of the mutation, the phenotype is inherited as a dominant trait. In humans, mutations in ribosomal proteins cause Diamond-Blackfan Anemia. However, no disease has yet been linked to mutations in human RPL38.

Gene

Function

Genetics

References

External links

Further reading