Genomics and Applied Biology 2018, Vol.9, No.5, 24-31
28
Figure 4 Protein-protein interaction network of TRK
2 Discussion
Studies have shown that the
TRK
gene is expressed in plants as well as in prokaryotic and eukaryotic
microorganisms. It plays an important role in maintaining the balance of intracellular and extracellular osmolarity
in the regulation of potassium ion metabolism. Potassium ion is closely related to the metabolic activities of
organisms and maintains the balance of potassium ion in the organism. Therefore, the importance of
TRK
genes
becomes more prominent and is a hot spot in the current biological research. At present, some studies on the
cloning and expression of
TRK
genes in microorganisms have been reported. Zhang et al. (2015) studied the
cloning and expression of the
TrkH
gene in marine micro-organisms. Ma et al. (2001) studied the expression of
brain-derived neurotrophic factor receptor trkB on NIH 3T3 cells. Guo et al. (2008) used homologous
recombination to replace the
TRK1
and
TRK2
genes of
Saccharomyces cerevisiae
with new genes amplified by
overlapping primers to obtain
S. cerevisiae
potassium-deficient strains, which is beneficial to the study of
potassium ion gene function. With the completion of genome sequencing of various species, identification and
analysis of gene family classification and relationship among members, sequence characteristics, evolutionary tree
characteristics and gene function prediction from the genome level have become important issues in the field of
life sciences.
To further understand the
TRK
genes in
Aspergillus niger
, the
TRK
gene family members of
Aspergillus niger
were identified and analyzed by bioinformatics methods, in which four
TRK
family members were identified. This
study analyzed the motifs, the structure distribution, length of exons and introns, and the genetic relationship of
the
TRK
gene family members systematically and comprehensively, which was beneficial to further understanding
TRK
functional characteristics. The
Trk
gene family includes four genes,
TrkH
,
TrkG
,
TrkA
and
TrkE
, of which
TrkH
is ubiquitous in
E. coli
and some intestinal bacteria (Wu, 2003). Schlösser et al. (1991) used gene cloning
and expression methods to find that
TrkA
and
TrkE
are regulatory proteins, while
TrkH
and
TrkG
are
transmembrane proteins. In this study, functional domains of the
TRK
genes of
Aspergillus niger
and yeast were
analyzed by Pfam software. It was concluded that the
TRK
gene family members in
Aspergillus niger
all belong to
TrkH
, which is a transmembrane protein. This structure may be related to the secretion system of
Aspergillus niger
.
The results provide theoretical basis for further understanding the function of
TRK
gene, researching the cation
transport system and osmoregulation mechanism of
Aspergillus niger
. In addition, the results provide a reference
for revealing the adaption of
Aspergillus niger
to the complex growth environment. These results also indicate that
