Two chitin metabolic enzyme genes from Hyriopsis cumingii: cloning, characterization, and potential functions

Abstract

ABSTRACT. Chitin, the second most important natural polymer in the world, and its N-deacetylated derivative chitosan are found in a wide variety of organisms. These versatile biopolymers are associated with a broad range of biological functions. This article is the first to report the potential functions of 2 chitin metabolic enzyme genes from Hyriopsis cumingii. A chitinase-3 gene (Chi-3) and a chitin deacetylase gene (Cda) were cloned from H. cumingii and characterized. Semi-quantitative reverse transcription polymerase chain reaction analysis revealed that the Cda gene was expressed in blood, mantle, liver, stomach, kidney, intestine, gill, and foot, whereas Chi-3 was also expressed in those tissues but not in blood. The tissue-specific expression of H. cumingii Chi-3 indicated that other Chi genes may be involved in the H. cumingii immune system. Real-time quantitative polymerase chain reaction analysis showed that the expression of Chi-3 was significantly (P < 0.05) upregulated 12 h after shell damage, suggesting that Chi-3 might hydrolyze superfluous chitin after shell recovery and play a role in shell formation. Conversely, Cda expression did not change significantly (P 4540 G.-L. Wang et al. ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 11 (4): 4539-4551 (2012) > 0.05) to maintain a certain degree of acetylation in chitin/chitosan. This study enriches the basic research on chitin metabolic genes and lays foundations for further research of shell regeneration in mussels.

Molecular Cloning of a Chitinase Gene from the Ovotestis of Kuroda’s Sea Hare &lt;i&gt;Aplysia kurodai&lt;/i&gt;

“…The full-length cDNA of A. kurodai ovotestis chitinase (AkChi) was 1352 bp in length and contained an ORF of 1263 bp encoding 421 amino acids (Figure 2). The size of ORF of AkChi was smaller than it from H. cumingii [14], 1962 bp encoding 653 amino acids. A poly-A sequence in eukaryotes was detected at the 3' end of AkChi.…”

“…The catalytic domain also contained an active site that is a conserved sequence of GH family 18 chitinases (Figure 3). Though the chitinase of H. cumingii [14] and E. scolopes [15] had two chitin binding domains (CBDs) and the chitinase of S. esculenta had one CBD, AkChi lacked a CBD. It was reported that fish chitinases have one CBD [8].…”

“…The stomach chitinases of fish have been identified and are classified into two groups, acidic fish chitinase-1 (AF-Case-1) and acidic fish chitinase-2 (AFCase-2) based on the differences in their primary structure and the activity toward short substrates [8]. Chitinases from molluscs play important physiological roles in the digestion of food [10] [11], attacking crustaceans [12], and shell formation [13] [14]. However, reports on the distribution, characterization, and cDNA cloning of molluscan chitinases are limited [10]- [16].…”

Identification and expression analysis of the MSP130-related-2 gene from Hyriopsis cumingii

“…Growth of the crystal is strictly regulated throughout mussel development, and various experimental systems have indicated that the proteins associated with shell formation differ on the basis of the genetic background of each particular species. A wide variety of bio-minerals play a key role in regulating the growth, shape and physical properties of materials, such as shells and pearls (Butler, 1998;Wilt, 1999;Fincham et al, 1999;Myllyharju and Kivirikko, 2001;Wang, et al, 2012).…”

Distribution of Chitinolytic Enzymes in the Organs and cDNA Cloning of Chitinase Isozymes from the Liver of Golden Cuttlefish &lt;i&gt;Sepia esculenta&lt;/i&gt;

“…Chitinases in the fish stomach are classified into two groups based on differences in their primary structure and the patterns of degradation of (GlcNAc) n : acidic fish chitinase-1 (AFCase-1) and acidic fish chitinase-2 (AFCase-2) [16] [17] [18] [19]. Conversely, studies reporting the cDNA cloning and expression of chitinases and chitinase-like proteins from bivalves and gastropods, which are mollusks, have noted that these play roles in shell formation [20] [21] [22], immunity [23] [24] [25] [26], and digestion [27]. Chitinase isozymes have been purified and studied from the liver of Decembrachiata (squid and cuttlefish), and are involved in digestion [28] [29] [30] [31].…”