LRRIQ3 (Leucine-rich repeats and IQ motif containing 3), which is also known as LRRC44, is a protein that in humans is encoded by the LRRIQ3 gene.[1] It is predominantly expressed in the testes, and is linked to a number of diseases.[2]
There are a total of 7 exons in the putative sequence of LRRIQ3.[3]
mRNA
Expression
LRRIQ3 is expressed as 2 primary isoforms, which produce proteins of length 624 amino acids and 464 amino acids respectively.[3] It is expressed at low levels in human and brown rat tissues,[4][5] with highest expression levels in testes tissue. There are relatively high expression levels in T cells, the epididymis, the kidney, and a number of glands.[6]
Protein
General Characteristics and Compositional Features
Human protein LRRIQ3 Isoform 1 consists of 624 amino acids, and has a molecular weight of 73.7 kDa. The isoelectric point of LRRIQ3 is 9.73, which suggests that LRRIQ3 is basic at normal physiological pH (~7.4).[7] Additionally, there is strong evidence that human LRRIQ3 localizes to the plasma membrane from antibody staining.[8] LRRIQ3 is rich in lysine residues, with a total of 82 lysines. It is also slightly low on glycines.[9]
No paralogs exists for LRRIQ3 in humans.[2] However, there are a number of orthologs, as reported by BLAST, some of which are listed below.[27] The number of years since divergence from the human protein, listed in "million of years ago (MYA)" below, were calculated using TimeTree.[28]
Orthologs to Human LRRIQ3 Protein (NP_001099129.1)
Genus and Species
Common Name
Divergence from Human Lineage (MYA)
Accession Number
Sequence length (aa)
Sequence Identity to Human Protein
Sequence Similarity to Human Protein
Gorilla gorilla gorilla
Gorilla
9.06
XP_004026030.1
624
97%
98%
Macaca mulatta
Rhesus monkey
29.44
XP_001097148.2
623
93%
95%
Ursus maritimus
Polar bear
96
XP_008689049.1
625
76%
87%
Felis catus
Domestic cat
96
XP_003990274.1
625
74%
86%
Camelus ferus
Bactrian camel
96
XP_006178380.1
618
73%
84%
Oryctolagus cuniculus
European rabbit
90
XP_002715603.1
622
71%
83%
Bison bison bison
American bison
96
XP_010847739.1
625
70%
82%
Trichechus manatus latirostris
Manatee
105
XP_004369192.1
623
70%
82%
Loxodonta africana
African elephant
105
XP_003411181.1
625
68%
80%
Condylura cristata
Star-nosed mole
96
XP_004679575.1
627
67%
80%
Eptesicus fuscus
Big brown bat
96
XP_008137759.1
621
66%
80%
Myotis davidii
Vesper bat
96
XP_006775977.1
618
65%
79%
Rattus norvegicus
Norway rat
90
NP_001019478.1
633
62%
77%
Mus Musculus
House mouse
90
NP_083214.2
633
63%
76%
Sorex araneus
Common shrew
96
XP_004603704.1
612
55%
73%
Chrysemys picta bellii
Painted turtle
312
XP_005285573.1
624
40%
56%
Pogona vitticeps
Bearded dragon
312
XP_020650341.1
651
35%
54%
Apteryx australis mantelli
Brown kiwi
312
XP_013800580.1
664
35%
54%
Struthio camelus australis
Southern Ostrich
312
XP_009685099.1
628
34%
51%
Clinical significance
LRRIQ3 is linked to a number of cancers. RNA-seq experiments have shown that LRRIQ3 is severely down-regulated (Log2-fold changes between -3.4 and -4.2) in a number of disease states, including pancreatic cancer, colorectal cancer, and breast cancer.[29][30][31]
↑Ren J, Wen L, Gao X, Jin C, Xue Y, Yao X (February 2009). "DOG 1.0: illustrator of protein domain structures". Cell Res. 19 (2): 271–3. doi:10.1038/cr.2009.6. ISSN1001-0602. PMID19153597.
↑Harder KW, Parsons LM, Armes J, Evans N, Kountouri N, Clark R, Quilici C, Grail D, Hodgson GS, Dunn AR, Hibbs ML (October 2001). "Gain- and loss-of-function Lyn mutant mice define a critical inhibitory role for Lyn in the myeloid lineage". Immunity. 15 (4): 603–15. doi:10.1016/s1074-7613(01)00208-4. ISSN1074-7613. PMID11672542.
↑Era T (July 2002). "Bcr-Abl is a "molecular switch" for the decision for growth and differentiation in hematopoietic stem cells". Int. J. Hematol. 76 (1): 35–43. PMID12138893.