Genomics and Applied Biology 2015, Vol. 6, No. 7, 1-8
1
Research Article Open Access
The
Neurospora crassa cmd
,
trm-9
, and
nca-2
Genes Play a Role in Growth,
Development, and Survival in Stress conditions
Laxmi V., Tamuli R.
Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781 039, India
Corresponding author email
Genomics and Applied Biology, 2015, Vol.6, No.7 doi: 10.5376/gab.2015.06.0007
Received: 24 Apr., 2015
Accepted: 02 Aug., 2015
Published: 11 Sep., 2015
© 2015 Laxmi V. and Tamuli R., This is an open access article published under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article:
Laxmi V. and Tamuli R., 2015, The
Neurospora crassa cmd
,
trm-9
, and
nca-2
Play a Role in Growth, Development, and Survival in Stress conditions,
Genomics and Applied Biology, Vol.6, No.7, 1-8
(doi
Abstract
The calmodulin protein antagonists, trifluoperazine (TFP) and chlorpromazine (CPZ) inhibit the growth, carotenoids
accumulation and sexual development of
Neurospora crassa
. In addition
, N. crassa
strains lacking
trm-9
, a cation-ATPase, showed
defect in growth. Moreover, strains lacking both
trm-9
and another
Ca
2+
-ATPase
nca-2
,
exhibited a severe growth defect, an
increased sensitivity to CaCl
2
, and a reduction in acquisition of thermotolerance induced by heat shock temperature. Therefore, the
cmd, trm-9,
and
nca-2
play a role in growth, survival in calcium stress and induced heat shock temperature in
N. crassa
.
Keywords
Calcium signaling; Ca
2+
/cation ATPases; Calmodulin;
Neurospora crassa
;
nca-2
; thermotolerance
Introduction
Calcium (Ca
2+
) signaling is involved in regulating
numerous processes in eukaryotes ranging from fungi
to mammals. The Ca
2+
-signaling process is initiated
primarily due to transient raise in concentration of
cytosolic free Ca
2+
([Ca
2+
]
c
), which is recognized by
Ca
2+
sensor proteins. One of the versatile and
evolutionary conserved Ca
2+
-sensor proteins is
calmodulin (CaM), which binds Ca
2+
with high
affinity and specificity. CaM plays an important role
in modulating DNA repair, DNA synthesis, cell
proliferation, cyclic nucleotide and glycogen metabolism,
secretion, motility and Ca
2+
transport (Means and
Dedman 1980; Smallwood et al., 2009). CaM also
plays an important role for the regulation of stress
response pathways in pathogenic fungi
Candida
albicans
and
Cryptococcus neoformans
(Kraus and
Heitman, 2003). In the budding yeast
Saccharomyces
cerevisiae
, CaM is required for mitotic progression
and acquisition of induced thermotolerance (Iida et al.,
1995). Similar to the
S. cerevisiae
, in the filamentous
fungi
Aspergillus nidulans
, CaM is critical for the
progression through the G2/M transition (Kahl and
Means 2003).
The filamentous fungus
Neurospora crassa
has a
unique calcium (Ca
2+
) signaling machinery, CaM is
encoded by NCU04120 that appears to be an essential
gene for viability (Galagan et al., 2003; Borkovich et
al
.,
2004; Tamuli et al.,
2013). In
N. crassa
, unlike the
vertebrate counterparts, only one CaM gene has been
identified (Capelli et al., 1993; Cox et al., 1982; Perez
et al., 1981; Galagan et al., 2003). In vertebrates, CaM
protein is encoded by multiple genes, for example, six
genes have been detected in zebra fish, three genes in
human and rat, two genes in frog and two genes in
chicken (Luan et al., 2007). Coding sequence of the
CaM encoding gene NCU04120 contains six exons
and five introns, and CaM possesses conserved
EF-hand domains (Tamuli et al., 2013). In
N. crassa
CaM antagonists, trifluoperazine (TFP) and
chlorpromazine (CPZ) caused shortening of period
length of the conidiation rhythm and light induced
phase shifting (Sadakane and Nakashima 1996;
Suzuki et al., 1996). In addition, possible role of CaM
in activation of chitin synthase enzyme in
N. crassa
was studied by examining the effects of TFP on
protoplast regeneration (Suresh and Subramanyam,
1997).
One of the targets of CaM is the Ca
2+
-ATPase, a Ca
2+
pump that help in fine tuning of Ca
2+
homeostasis in
cells by pumping Ca
2+
out of cells. Ca
2+
-ATPases
hydrolyze ATP to catalyze active Ca
2+
-efflux across
biological membranes, and maintain a steep Ca
2+
gradient across the plasma membrane (Hao et al.,
