Leucine rich repeat containing 7 also known as LRRC7, Densin-180, or LAP1 is a
protein which in humans is encoded by the ''LRRC7''
gene.
Structure
Found to be densely associated to the
postsynaptic density (PSD), it has been characterised as a 188 kDa (originally thought to be 180 kDa, hence nomenclature), 1495 residues long, brain-specific protein containing 16
leucine-rich repeat
A leucine-rich repeat (LRR) is a protein structural motif that forms an α/β horseshoe fold. It is composed of repeating 20–30 amino acid stretches that are unusually rich in the hydrophobic amino acid leucine. These tandem repeats common ...
s (LRRs) within the 500
N-terminal
The N-terminus (also known as the amino-terminus, NH2-terminus, N-terminal end or amine-terminus) is the start of a protein or polypeptide, referring to the free amine group (-NH2) located at the end of a polypeptide. Within a peptide, the ami ...
residues, and one Psd95/Discs large/Zona occludens (
PDZ) domain within the 200
C-terminal residues. Originally postulated to have an apparent transmembrane domain, it has now been shown that the protein has numerous
phosphorylation
In chemistry, phosphorylation is the attachment of a phosphate group to a molecule or an ion. This process and its inverse, dephosphorylation, are common in biology and could be driven by natural selection. Text was copied from this source, wh ...
sites both N- and C-term of this domain, and that protein is therefore
cytoplasmic;
palmitoylation is thought to occur near the N-terminus of the protein which would account for localisation of the protein at the PSD.
Interactions
LRRC7 has been shown to
interact
Advocates for Informed Choice, dba interACT or interACT Advocates for Intersex Youth, is a 501(c)(3) nonprofit organization using innovative strategies to advocate for the legal and human rights of children with intersex traits. The organizati ...
with
CDH2.
The currently exposed interactions of Densin-180 portray the protein as a promiscuous player amongst key synaptic players, fitting with the original observation of the protein’s dense presence among core PSD proteins by
Mary B. Kennedy
Mary Bernadette Kennedy (born 1947) is an American biochemist and neuroscientist. She is a member of the American Academy of Arts and Sciences, and is the Allen and Lenabelle Davis Professor of Biology at the California Institute of Technology, w ...
's Laboratory. Identified interaction partners include: CaMKII-alpha, alpha-Actinin and NR2B (via CaMKII-alpha), Cav1.3 (L-type Ca2+) channels, MAGUIN-1, Shank, PSD-95 (via Shank and MAGUIN-1), beta-Catenin, delta-Catenins and NCadherin (via the Catenins). The nature and function of these interactions, detailed in tables 1-1 and 1-2, portray Densin-180 as a key interactor in the midst of receptor proteins, scaffolding proteins and structural proteins. [number of sources - referenced in - Subcellular localisation of recombinant Densin-180 clones expressed in HEK293 TSA cells Ranatunga, J.M. (2011) Subcellular localisation of recombinant Densin-180 clones expressed in HEK293 TSA cells. Masters thesis, UCL (University College London). http://discovery.ucl.ac.uk/1322972/]
It is also quite possible that Densin-180 dimerises or multimerises through interactions between its PDZ domain and its own terminal amino acid residues. [Subcellular localisation of recombinant Densin-180 clones expressed in HEK293 TSA cells
Ranatunga, J.M. (2011) Subcellular localisation of recombinant Densin-180 clones expressed in HEK293 TSA cells. Masters thesis, UCL (University College London). http://discovery.ucl.ac.uk/1322972/]
References
Further reading
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{{refend
Add—a very detailed thesis with preliminary experiments and theories about the function of Densin-180 entitled Subcellular localisation of recombinant Densin-180 clones expressed in HEK293 TSA cells
http://discovery.ucl.ac.uk/1322972/
LRR proteins