Protein unc-13 homolog D, also known as munc13-4, 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 ''UNC13D''
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 ...
.
Function
Munc13-4 is a member of the UNC13 family, containing similar domain structure as other family members but lacking an
N-terminal phorbol
Phorbol is a natural, plant-derived organic compound. It is a member of the tigliane family of diterpenes. Phorbol was first isolated in 1934 as the hydrolysis product of croton oil, which is derived from the seeds of the purging croton, ''Croton ...
ester-binding
C1 domain
C1 domain (also known as phorbol esters/diacylglycerol binding domain) binds an important secondary messenger diacylglycerol (DAG), as well as the analogous phorbol esters. Phorbol esters can directly stimulate protein kinase C, PKC.
Phorbol es ...
present in other Munc13 proteins. The protein appears to play a role in
vesicle
Vesicle may refer to:
; In cellular biology or chemistry
* Vesicle (biology and chemistry)
In cell biology, a vesicle is a structure within or outside a cell, consisting of liquid or cytoplasm enclosed by a lipid bilayer. Vesicles form nat ...
maturation during
exocytosis and is involved in regulation of
cytolytic granules secretion.
Munc13-4 is an essential protein in the intracellular
trafficking
Smuggling is the illegal transportation of objects, substances, information or people, such as out of a house or buildings, into a prison, or across an international border, in violation of applicable laws or other regulations.
There are various ...
and exocytosis of lytic granules. It is targeted to
CD63
CD63 antigen is a protein that, in humans, is encoded by the ''CD63'' gene. CD63 is mainly associated with membranes of intracellular vesicles, although cell surface expression may be induced.
Function
The protein encoded by this gene is a mem ...
positive secretory lysosomes. The C-terminal
C2 domain
A C2 domain is a protein structural domain involved in targeting proteins to cell membranes. The typical version (PKC-C2) has a beta-sandwich composed of 8 β-strands that co-ordinates two or three calcium ions, which bind in a cavity formed by ...
of the protein is involved in this process.
Clinical significance
Mutations in the UNC13D gene are associated with
hemophagocytic lymphohistiocytosis
Hemophagocytic lymphohistiocytosis (HLH), also known as haemophagocytic lymphohistiocytosis (British spelling), and hemophagocytic or haemophagocytic syndrome, is an uncommon hematologic disorder seen more often in children than in adults. It is a ...
type 3.
References
Further reading
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External links
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{{gene-17-stub