emerging-diseases-influenza-2018-accepted-abstracts

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Microbiology: Current Research

Volume 2

International Conference on

Emerging Diseases, Outbreaks & Case Studies

Annual Meeting on

March 28-29, 2018 | Orlando, USA

Influenza

eucine rich repeats (LRRs) are unusually rich in the

hydrophobic, amino acid leucine. LRRs have been reported

in over 100,000 proteins from viruses to eukaryotes. The

LRRs are composed of 20-30 residues stretches and repeat

in tandem. The repeat numbers range from two to ninety-

seven. LRR units are divided into a highly conserved segment

(HCS) and a variable segment (VS). Twenty-three types

of LRRs including eight classes well recognized have been

proposed. The HCS part consists of an eleven or twelve

residue stretch, LxxLxLxx(N/C)(x/-)L, in which “L” is Leu, Ile,

Val, or Phe, “N” is Asn, Thr, Ser, or Cys, “C” is Cys, Ser or Asn,

“x” is any amino acid, and “-“ is a deletion. Three residues

at positions 3 to 5 in the HCS part form a short β-strand.

These β-strands stack parallel; they have the pattern of

H-bonding (N-H → O=C), and then tandem repeats of LRRs

assume their super helical arrangements called a solenoid

structure. Structural data of LRR proteins have increased.

Meanwhile, a number of human diseases have been shown

to be associated with mutation in the genes encoding LRR

proteins which count over forty. The LRR proteins include

opticin, lumican, fibromodulin, FLRT3, F-box/LRR-repeat

protein 4, LGI1, Trk-A, nyctalopin, FSHR, LH/CGR, TSHR,

keratocan, GPIb, GPIb, GPIX, LRRK2, CIAS1, CIITA, and

Nod2. The mutations of these proteins are associated with

high myopia, congenital hypogonadotropic hypogonadism,

mitochondrial encephalomyopathy, ADLTE/ADPEAF, CIPA,

CSNB1/XLCSNB, ODG1, LCH, Graves disease, thyrotropin

resistance, FGH, papillary cancer, hyperthyroidism, CNA2,

BSS, PT-vWD, Parkinson’s disease, CINCA/NOMID, BLS II, and

Crohn’s disease. The mutations occur frequently within the

LRR domains as well as in their neighboring domains at the

N- and C-termini. Here, we review the adverse effects of

different sequence variants based on the sequence analysis

of the LRR domains and the known structures of LRR proteins.

Human diseases related with leucine rich repeats

Norio Matsushima

Sapporo Medical University, Japan