WD Repeat and Coiled-coiled containing protein (WDCP) is a protein which in humans is encoded by the WDCP gene. The function of the protein is not completely understood, but WDCP has been identified in a fusion protein with anaplastic lymphoma kinase found in colorectal cancer. WDCP has also been identified in the MRN complex, which processes double-stranded breaks in DNA.
Gene
WDCP is located in chromosome 2, specifically locus 2p23.3 on the minus strand, in humans. The total gene is 20,235 bp long, from 24,029,340 – 24,047,575. WDCP is located in between the MFSD2B and FKBP1B genes. The total gene contains 4 exons, the details of which can be seen in the table below.
Table 1. Exons of WDCP and their various lengths.
Common aliases of the gene include chromosome 2, open reading frame 44 (c2orf44), MMAP, and PP384.
mRNA
The WDCP isoform 1 is encoded by mRNA-WD repeat and coiled-coil containing, transcript variant 1. The total RNA transcript is 18,045 bp long and is transcribed from the WDCP gene from nucleotides 24,029,347 - 24,047,391. The coding DNA sequence is 3848 nucleotides long. The 5’ UTR contains 7,897 nucleotides, and the 3’ UTR contains 1,597 nucleotides.
There are two known transcript variants of WDCP: WDCP transcript variant 2 and WDCP transcript variant X1. Information about the two transcripts can be seen below.
Table 2. Transcript Variants of WDCP with their alternative splicing pattern in comparison to WDCP transcript variant 1.
Protein
Primary sequence
WDCP protein isoform 1 is 721 amino acids in length. Its molecular weight is 79 kDa and the theoretical isoelectric point is 6.2. The protein sequence for WDCP Protein Isoform 1 is shown below.
1 MELGKGKLLR TGLNALHQAV HPIHGLAWTD GNQVVLTDLR LHSGEVKFGD SKVIGQFECV
61 CGLSWAPPVA DDTPVLLAVQ HEKHVTVWQL CPSPMESSKW LTSQTCEIRG SLPILPQGCV
121 WHPKCAILTV LTAQDVSIFP NVHSDDSQVK ADINTQGRIH CACWTQDGLR LVVAVGSSLH
181 SYIWDSAQKT LHRCSSCLVF DVDSHVCSIT ATVDSQVAIA TELPLDKICG LNASETFNIP
241 PNSKDMTPYA LPVIGEVRSM DKEATDSETN SEVSVSSSYL EPLDLTHIHF NQHKSEGNSL
301 ICLRKKDYLT GTGQDSSHLV LVTFKKAVTM TRKVTIPGIL VPDLIAFNLK AHVVAVASNT
361 CNIILIYSVI PSSVPNIQQI RLENTERPKG ICFLTDQLLL ILVGKQKLTD TTFLPSSKSD
421 QYAISLIVRE IMLEEEPSIT SGESQTTYST FSAPLNKANR KKLIESLSPD FCHQNKGLLL
481 TVNTSSQNGR PGRTLIKEIQ SPLSSICDGS IALDAEPVTQ PASLPRHSST PDHTSTLEPP
541 RLPQRKNLQS EKETYQLSKE VEILSRNLVE MQRCLSELTN RLHNGKKSSS VYPLSQDLPY
601 VHIIYQKPYY LGPVVEKRAV LLCDGKLRLS TVQQTFGLSL IEMLHDSHWI LLSADSEGFI
661 PLTFTATQEI IIRDGSLSRS DVFRDSFSHS PGAVSSLKVF TGLAAPSLDT TGCCNHVDGM
721 A
Figure 1. Protein sequence of WDCP protein isoform 1.
Compositional analysis of WDCP Isoform 1 shows no extremely high or low levels of particular amino acids. The protein contains no positive, negative, or mixed charged clusters.
There are two isoforms of WDCP, as seen in the table below.
Table 3. Table of WDCP protein Isoforms and Protein Information.
Secondary structure
The secondary structure of WDCP Protein Isoform 1 consists of 47 random coils (429 residues, 59.5%), 19 alpha-helices (160 residues, 22.19%), and 31 extended strands (132 residues, 18.31%).
Tertiary and quaternary structure
There are two predicted disulfide bonds in WDCP, one between cysteine residues 574 and 623, and the other between cysteine residues 713 and 714.
Domains and motifs
WDCP protein domains include two tryptophan-aspartic acid repeat sites, multiple phosphorylation sites, and a domain that interacts with the hemopoietic cell kinase.
Tissue expression
Across various tissue types, WDCP shows increased mRNA expression in white blood cells (3.0 RPKM), thymus (3.6 RPKM), lymph nodes, bone marrow, and testes. WDCP exhibits increased protein expression in endocrine tissues, and well as the kidney and urinary bladder. Across multiple tissue lines in the GTEx database, WDCP expression seemed to be highest in Epstein-Barr Virus transformed lymphocytes and lowest in the pancreas. NCBI GEO Records reveal that overall WDCP expression is in the 65-70th percentile according to the Universal Human Reference RNA.
In fetal tissue, WDCP mRNA expression is highest in the lung at 17 weeks at 3.75 RPKM, the heart at 10 weeks at 3.5 RPKM, and in the intestine at 11 weeks 3.0 RPKM. At 17 weeks, WDCP expression in the intestine drops down from 3.0 RPKM to 0.75 RPKM. The fetal kidney at 20 weeks exhibits the lowest WDCP expression, at 0.5 RPKM.