High impact information on CHS2

• Using degenerate oligonucleotide mixtures designed on the basis of conserved sequences of the Saccharomyces cerevisiae CHS1 and CHS2 polypeptides, a DNA fragment encoding a similar predicted amino acid sequence was amplified from N. crassa genomic DNA [1].
• Exit from mitosis triggers Chs2p transport from the endoplasmic reticulum to mother-daughter neck via the secretory pathway in budding yeast [2].
• We report that Chs2p was restrained in the endoplasmic reticulum (ER) during metaphase [2].
• Budding yeast chitin synthase 2 (Chs2p), which lays down the primary septum, localizes to the mother-daughter neck in telophase [2].
• In contrast, Chs3p is synthesized constitutively and is metabolically stable, indicating that Chs2p and Chs3p are subject to different modes of regulation [3].

Biological context of CHS2

• Genetic evidence indicated that a mutant lacking all three chitin synthases was inviable; this was confirmed by constructing a triple mutant rescued by a plasmid carrying a CHS2 gene under control of a GAL1 promoter [4].
• The phenotype of a delta chs2 null mutant suggested that CHS2 encoded the major enzyme activity in vitro and was largely responsible for elevated chitin synthase activities in microsomal preparations from hyphal cells compared to yeast cells [5].
• Chitin septum biogenesis is catalyzed by two distinct chitin synthase activities encoded by the CHS2 and CHS3 genes [6].
• FpCHS1 and FpCHS2 were homologous to regions of CHS1 and CHS2 of Saccharomyces cerevisiae, and their derived amino acid sequences fell into chitin synthase classes I and II, respectively [7].
• The catalytic subunit of each of these activities is encoded by separated genes, CHS1, CHS2 and CHS3, respectively, although it has been shown in S. cerevisiae that CSIII activity also depends on the products of other genes [8].

Anatomical context of CHS2

• The three chitin synthases of Saccharomyces cerevisiae, Chs1, Chs2, and Chs3, participate in septum and cell wall formation of vegetative cells and in wall morphogenesis of conjugating cells and spores [9].
• Chs2p degradation depends on the vacuolar protease encoded by PEP4, indicating that Chs2p is destroyed in the vacuole [3].
• As in the case of Chs1, most of the Chs2 activity was found to be associated with the plasma membranes [10].

Associations of CHS2 with chemical compounds

• By transferring cells carrying CHS2 under the control of a GAL1 promoter from galactose-containing medium to glucose-containing medium, transcription of CHS2 was shut off [9].
• BACKGROUND: In S. cerevisiae the beta-1,4-linked N-acetylglucosamine polymer, chitin, is synthesized by a family of 3 specialized but interacting chitin synthases encoded by CHS1, CHS2 and CHS3 [11].
• Alanine substitutions for the conserved amino acids in con2 identified five amino acids, Asn797, His799, Asp800, Trp803, and Thr805, the mutation of which severely diminished enzymatic activity and the enzyme's ability to rescue the yeast chs2 delta chs3 delta null mutant strain [12].
• Arginine residue mutations in Chs3p, and in Chs1p and Chs2p, resulted in a loss of both function in vivo and enzymatic activity [13].
• Chs2 also shows less sensitivity than Chs1 to inhibition by polyoxin D or sodium chloride, a property that was used to demonstrate the presence of Chs2 in wild-type extracts [10].

Regulatory relationships of CHS2

• Cell cycle-regulated trafficking of Chs2 controls actomyosin ring stability during cytokinesis [14].

Other interactions of CHS2

• Chitin synthases I and II, the products of the CHS1 and CHS2 genes, respectively, are closely related proteins that require partial proteolysis for activity in vitro [15].
• Chs2p differs from Myo1p in that it reflects the changes in shape of the plasma membrane to which it is attached and in that it is packed after its action into visible endocytic vesicles for its disposal [16].
• Furthermore, the septin Cdc12p, fused with yellow or cyan fluorescent protein, also colocalized with Myo1p and Chs2p at the aberrant locations [16].
• The RSF1 gene is distinct from the CHS2 chitin synthase gene that is responsible for septation, and thus RSF1 most likely encodes a regulator of chitin synthesis [17].
• When chitin synthase 2 of Saccharomyces cerevisiae was overexpressed in yeast cells using GAL1 promoter, deletion of the N-terminal 193 amino acids significantly increased the level of the protein without affecting its characteristics [18].

Analytical, diagnostic and therapeutic context of CHS2

• Chitin synthase 2 of Saccharomyces cerevisiae was characterized by means of site-directed mutagenesis and subsequent expression of the mutant enzymes in yeast cells [19].

References