Shroom protein family
Encyclopedia
In molecular biology, the Shroom protein family is a small group of related protein
s that are defined by sequence
similarity and in most cases by some link to the actin cytoskeleton. The Shroom (Shrm) protein family
is found only in animal
s. Proteins
of this family are predicted to be utilised in multiple morphogenic and developmental processes across animal phyla
to regulate cells
shape or intracellular
architecture in an actin and myosin-dependent manner. While the founding member of the Shrm family is Shrm1 (formerly Apx), it appears that this protein is found only in Xenopus
. In mice
and humans, the Shrm family of proteins
consists of:
This protein family is based on the conservation
of a specific arrangement of an N-terminal PDZ domain, a centrally positioned sequence motif
termed ASD1 (Apx/Shrm Domain 1) and a C-terminal motif termed ASD2. Shrm2 and Shrm3 contain all three domains, while Shrm4 contains the PDZ and ASD2 domains, but lacks a discernible ASD1 element. To date, the ASD1 and ASD2 elements have only been found in Shrm-related proteins and do not appear in combination with other conserved
domains
. ASD1 is required for targeting actin, while ASD2 is capable of eliciting an actomyosin based constriction event. ASD2 is the most highly conserved sequence
element shared by Shrm1, Shrm2, Shrm3, and Shrm4. It possesses a well conserved series of leucine
residues that exhibit spacing consistent with that of a leucine zipper
motif
.
Shroom2 is both necessary and sufficient to govern the localization of pigment granules at the apical
surface of epithelial cells. Shroom2 is a central regulator of RPE pigmentation. Despite their diverse biological
roles, Shroom family proteins share a common activity. Since the locus
encoding human
SHROOM2 lies within the critical region for two distinct forms of ocular albinism, it is possible that SHROOM2 mutations may contribute to human visual system disorders.
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
s that are defined by sequence
Sequence (biology)
A sequence in biology is the one-dimensional ordering of monomers, covalently linked within in a biopolymer; it is also referred to as the primary structure of the biological macromolecule.-See also:* Protein sequence* DNA sequence...
similarity and in most cases by some link to the actin cytoskeleton. The Shroom (Shrm) protein family
Protein family
A protein family is a group of evolutionarily-related proteins, and is often nearly synonymous with gene family. The term protein family should not be confused with family as it is used in taxonomy....
is found only in animal
Animal
Animals are a major group of multicellular, eukaryotic organisms of the kingdom Animalia or Metazoa. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their life. Most animals are motile, meaning they can move spontaneously and...
s. Proteins
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
of this family are predicted to be utilised in multiple morphogenic and developmental processes across animal phyla
Phylum
In biology, a phylum The term was coined by Georges Cuvier from Greek φῦλον phylon, "race, stock," related to φυλή phyle, "tribe, clan." is a taxonomic rank below kingdom and above class. "Phylum" is equivalent to the botanical term division....
to regulate cells
Cell (biology)
The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....
shape or intracellular
Intracellular
Not to be confused with intercellular, meaning "between cells".In cell biology, molecular biology and related fields, the word intracellular means "inside the cell".It is used in contrast to extracellular...
architecture in an actin and myosin-dependent manner. While the founding member of the Shrm family is Shrm1 (formerly Apx), it appears that this protein is found only in Xenopus
Xenopus
Xenopus is a genus of highly aquatic frogs native to Sub-Saharan Africa. There are 19 species in the Xenopus genus...
. In mice
MICE
-Fiction:*Mice , alien species in The Hitchhiker's Guide to the Galaxy*The Mice -Acronyms:* "Meetings, Incentives, Conferencing, Exhibitions", facilities terminology for events...
and humans, the Shrm family of proteins
Protein family
A protein family is a group of evolutionarily-related proteins, and is often nearly synonymous with gene family. The term protein family should not be confused with family as it is used in taxonomy....
consists of:
- Shrm2 (formerly Apxl), a protein involved in the morphogenesis, maintenance, and/or function of vascular endothelial cells.
- Shrm3 (formerly Shroom), a protein necessary for neural tubeNeural tubeIn the developing vertebrate, the neural tube is the embryo's precursor to the central nervous system, which comprises the brain and spinal cord...
closure in vertebrateVertebrateVertebrates are animals that are members of the subphylum Vertebrata . Vertebrates are the largest group of chordates, with currently about 58,000 species described. Vertebrates include the jawless fishes, bony fishes, sharks and rays, amphibians, reptiles, mammals, and birds...
developmentDevelopmental biologyDevelopmental biology is the study of the process by which organisms grow and develop. Modern developmental biology studies the genetic control of cell growth, differentiation and "morphogenesis", which is the process that gives rise to tissues, organs and anatomy.- Related fields of study...
as deficiency in Shrm results in spina bifida. Shrm3 is also conservedConserved sequenceIn biology, conserved sequences are similar or identical sequences that occur within nucleic acid sequences , protein sequences, protein structures or polymeric carbohydrates across species or within different molecules produced by the same organism...
in some invertebrates, as orthologues can be found in sea urchinSea urchinSea urchins or urchins are small, spiny, globular animals which, with their close kin, such as sand dollars, constitute the class Echinoidea of the echinoderm phylum. They inhabit all oceans. Their shell, or "test", is round and spiny, typically from across. Common colors include black and dull...
s.
- Shrm4, a regulator of cyto-skeletal architecture that may play an important role in vertebrate development. It is implicated in X-linked mental retardationMental retardationMental retardation is a generalized disorder appearing before adulthood, characterized by significantly impaired cognitive functioning and deficits in two or more adaptive behaviors...
in humans.
This protein family is based on the conservation
Conserved sequence
In biology, conserved sequences are similar or identical sequences that occur within nucleic acid sequences , protein sequences, protein structures or polymeric carbohydrates across species or within different molecules produced by the same organism...
of a specific arrangement of an N-terminal PDZ domain, a centrally positioned sequence motif
Sequence motif
In genetics, a sequence motif is a nucleotide or amino-acid sequence pattern that is widespread and has, or is conjectured to have, a biological significance...
termed ASD1 (Apx/Shrm Domain 1) and a C-terminal motif termed ASD2. Shrm2 and Shrm3 contain all three domains, while Shrm4 contains the PDZ and ASD2 domains, but lacks a discernible ASD1 element. To date, the ASD1 and ASD2 elements have only been found in Shrm-related proteins and do not appear in combination with other conserved
Conserved sequence
In biology, conserved sequences are similar or identical sequences that occur within nucleic acid sequences , protein sequences, protein structures or polymeric carbohydrates across species or within different molecules produced by the same organism...
domains
Protein domain
A protein domain is a part of protein sequence and structure that can evolve, function, and exist independently of the rest of the protein chain. Each domain forms a compact three-dimensional structure and often can be independently stable and folded. Many proteins consist of several structural...
. ASD1 is required for targeting actin, while ASD2 is capable of eliciting an actomyosin based constriction event. ASD2 is the most highly conserved sequence
Sequence
In mathematics, a sequence is an ordered list of objects . Like a set, it contains members , and the number of terms is called the length of the sequence. Unlike a set, order matters, and exactly the same elements can appear multiple times at different positions in the sequence...
element shared by Shrm1, Shrm2, Shrm3, and Shrm4. It possesses a well conserved series of leucine
Leucine
Leucine is a branched-chain α-amino acid with the chemical formula HO2CCHCH2CH2. Leucine is classified as a hydrophobic amino acid due to its aliphatic isobutyl side chain. It is encoded by six codons and is a major component of the subunits in ferritin, astacin and other 'buffer' proteins...
residues that exhibit spacing consistent with that of a leucine zipper
Leucine zipper
A leucine zipper, aka leucine scissors, is a common three-dimensional structural motif in proteins. These motifs are usually found as part of a DNA-binding domain in various transcription factors, and are therefore involved in regulating gene expression...
motif
Sequence motif
In genetics, a sequence motif is a nucleotide or amino-acid sequence pattern that is widespread and has, or is conjectured to have, a biological significance...
.
Shroom2 is both necessary and sufficient to govern the localization of pigment granules at the apical
Apical
Apical, from the Latin apex meaning to be at the apex or tip, may refer to:*Apical , an anatomical term of location for features associated with the base of an organism or structure...
surface of epithelial cells. Shroom2 is a central regulator of RPE pigmentation. Despite their diverse biological
Biology
Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, origin, evolution, distribution, and taxonomy. Biology is a vast subject containing many subdivisions, topics, and disciplines...
roles, Shroom family proteins share a common activity. Since the locus
Locus
The word locus is Latin for "place". It can mean:-Positions:*Locus of control, in industrial psychology, having an internal or external locus of control...
encoding human
Human
Humans are the only living species in the Homo genus...
SHROOM2 lies within the critical region for two distinct forms of ocular albinism, it is possible that SHROOM2 mutations may contribute to human visual system disorders.