Isolation of cDNAs encoding a substrate for protein kinase C: Nucleotide sequence and chromosomal mapping of the gene for a human 80K protein

Sakai, Kosuke; Hirai, Masamichi; Minoshima, Shinsei; Kudoh, Jun; Fukuyama, Ryuichi; Shimizu, Nobuyoshi

doi:10.1016/0888-7543(89)90063-3

Cited by 65 publications

(47 citation statements)

References 23 publications

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“…In a microarray screen designed to identify proteins that respond similarly to vitamin D and/or altered dietary Ca 2ϩ intake as TRPV5, Gkika et al (22) identified 80K-H. 80K-H was originally cloned as a PKC substrate of 80 kDa and was subsequently associated with intracellular signaling (52). However, these studies did not resolve the biological function of this protein.…”

Section: K-hmentioning

confidence: 99%

Regulation of TRPV5 and TRPV6 by associated proteins

Graaf

Hoenderop²,

Bindels³

2006

American Journal of Physiology-Renal Physiology

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The epithelial Ca 2ϩ channels TRPV5 and TRPV6 are the most Ca 2ϩ -selective members of the TRP channel superfamily. These channels are the prime target for hormonal control of the active Ca 2ϩ flux from the urine space or intestinal lumen to the blood compartment. Insight into their regulation is, therefore, pivotal in our understanding of the (patho)physiology of Ca 2ϩ homeostasis. The recent elucidation of TRPV5/ 6-associated proteins has provided new insight into the molecular mechanisms underlying the regulation of these channels. In this review, we describe the various means of TRPV5/6 regulation, the role of channel-associated proteins herein, and the relationship between both processes. Rab11; calbindin; 80KH; BSPRY; Klotho; kidney TRANSCELLULAR Ca 2ϩ (re)absorption is a pivotal process in the maintenance of extracellular Ca 2ϩ balance. It allows the organism to respond to fluctuations in dietary Ca 2ϩ and adapt to the body's demand during processes such as growth, pregnancy, lactation, and aging. The first step in transcellular transport is the influx of Ca 2ϩ across the apical membrane of the epithelial cell, which is a tightly controlled mechanism (Fig. 1). Next, Ca 2ϩ enters the cell and is sequestered by specialized proteins called calbindins to maintain low cytosolic Ca 2ϩ concentrations. Subsequently, bound Ca 2ϩ diffuses to the basolateral side of the cell, where it is extruded into the bloodstream via the Na ϩ /Ca 2ϩ exchanger (NCX1) and plasma membrane Ca 2ϩ -ATPase (PMCA1b). The molecular identification of two members of the transient receptor potential (TRP) superfamily, TRPV5 (28) and TRPV6 (48), boosted the research addressing the molecular mechanism of epithelial Ca 2ϩ transport. The physiological role of these channels has been substantiated in several mouse models of Ca 2ϩ -related disorders, including vitamin D deficiency rickets type I (VDDR-I) (13, 25) and vitamin D-resistant rickets type II (60) (VDDR-II). Furthermore, TRPV5 (29) and TRPV6 (3) knockout mice show significant disturbances in their Ca 2ϩ homeostasis. TRPV5 primarily fulfills the role as gatekeeper of epithelial Ca 2ϩ transport in the kidney (27), whereas TRPV6 forms the main Ca 2ϩ influx pathway in the small intestine (41). Therefore, detailed insight into the molecular regulation of TRPV5/6 is pivotal to our understanding of Ca 2ϩ homeostasis. STRUCTURAL FEATURES OF TRPV5 AND TRPV6TRPV5 and TRPV6 display the highest sequence homology with the vanilloid receptor subfamily (TRPV) of TRP channels. These channels share a predicated topology consisting of large intracellular NH 2 -and COOH-terminal tails flanking six transmembrane segments (TM) and an additional hydrophobic stretch between TM5 and TM6, forming the pore-forming region (Fig. 2). Several TRP channels contain ankyrin repeats in their NH 2 terminus. The number of ankyrin repeats range from 0 to 14, and the members of the TRPV subfamily have 3-4 repeats (12), varying slightly depending on the sequencesimilarity algorithm used. TRPV5 and TRPV6 display several prope...

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Section: K-hmentioning

confidence: 99%

Regulation of TRPV5 and TRPV6 by associated proteins

Graaf

Hoenderop²,

Bindels³

2006

American Journal of Physiology-Renal Physiology

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“…Total cellular RNA was prepared from COS-1 confluent cells by the LiCl/urea method [23] and dissolved in 20 pl H,O; 10 pg was subjected to electrophoresis in 1% agarose gels containing 20mM Mops pH 7.0, 5 mM sodium acetate, 0.1 mM EDTA and 7% formaldehyde for 8 h. The RNA was transferred to Biodyne B membranes (Pall BioSupport Inc., IL, USA) and probed with 32P-labeled EcoRI -HincII fragment (1.4 kb) of murine Pl-4GalT cDNA.…”

Section: Northern Hybridization Analysismentioning

confidence: 99%

Characterization of a murine β1‐4galactosyltransferase expressed in COS‐1 cells

Nakazawa

Furukawa

Kobata

et al. 1991

European Journal of Biochemistry

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We inserted a full-length murine cDNA, which had been isolated from F9 embryonal carcinoma cells by using a bovine lactose synthetase A protein cDNA as a probe, in a mammalian expression vector (pCMGT1) and expressed it in COS-1 cells to characterize the pCMGTl -directed enzyme. The galactosyltransferase activity toward asialo-agalacto-transferrin (AsAg-Tf) in the pCMGTl -transfected cells was approximately eightfold higher than that in mock-or non-transfected cells. In contrast, no difference was observed in the specific activity of galactose transfer between pCMGTl -transfected cells and mock-or non-transfected cells when asialo-ovine submaxillary mucin were used as an acceptor. Since almost all [3H]galactose incorporated into the AsAg-Tf was released by digestion with streptococcal j-galactosidase, most of the linkage created by this enzyme was in the Galbl-4GlcNAc group.The acceptor specificity of the pCMGTl -directed enzyme was changed from N-acetylglucosamine to glucose by adding a-lactalbumin in the reaction mixture. a-Lactalbumin also partially inhibited the galactose transfer to AsAg-Tf. The kinetic study revealed that the apparent K, values of the pCMGT1-directed enzyme for N-acetylglucosamine, AsAg-Tf and UDP-Gal are 2 mM, 60 pM and 24 pM, respectively.These results indicated that the murine cDNA isolated from F9 cells encodes an active enzyme which catalyzes not only the lactose synthesis but also the transfer of galactose to N-acetylglucosamine residues of Asn-linked sugar chains of glycoproteins in a j1-4 linkage The carbohydrate moieties of glycoproteins, glycolipids and proteoglycans are synthesized through a series of sugar chain elongation reactions which are catalyzed by specific glycosyltransferases [l]. A fl1-4galactosyltransferase (UDPGal :N-acetylglucosamine /?1-4galactosyltransferase ; PI -4-GalT is a member of the glycosyltransferase family. This enzyme catalyzes the transfer of galactose from UDP-Gal to N-acetylglucosamine (GlcNAc) with the specific intersugar linkage, Galpl-4GlcNAc. During the last two decades, a number of investigators have reported the purification and characterization of jl-4GalTs from various sources such as human and bovine milk [2, 31, swine [ll]. Among these /31-4GalTs, a milk b1-4GalT (lactose synthetase A protein) is capable of recognizing glucose as an acceptor in the presence of a-lactalbumin (lactose synthetase B protein) [12]. The fll-4GalT activities purified from other tissues toward N-acetylglucosamine were also reported to be inhibited by a-lactalbumin, and the acceptor specificities of these b1-4GalTs were analogous to thatCorrespondence to H. Narimatsu,

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“…The variable exon repertoire expressed by different isoforms is known to greatly influence the charge properties of CD45 since the region encoded by these exons contains multiple sites for O-linked glycosylation (2). CD45 also possesses [11][12][13][14][15][16][17][18] putative N-linked glycosylation sites, which are subject to cell-specific controls, conferring further microheterogeneity upon CD45 (3). It has been estimated that approximately one third of the total molecular weight of mature CD45 is contributed by carbohydrates, which vary qualitatively and quantitatively depending on the particular cell and isoform(s) expressed (3).…”

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confidence: 99%

Identification of the CD45-associated 116-kDa and 80-kDa Proteins as the α- and β-Subunits of α-Glucosidase II

Arendt¹,

Ostergaard

1997

Journal of Biological Chemistry

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CD45 is an abundant, highly glycosylated transmembrane protein-tyrosine phosphatase expressed on hematopoietic cells. Herein we demonstrate that two proteins of 116 kDa and 80 kDa copurify with CD45 from mouse T cells. Microsequence analysis of the 116-kDa protein revealed high similarity to an incomplete human open reading frame that has been suggested to correspond to the catalytic ␣-subunit of glucosidase II. We determined the nucleotide sequence of the mouse cDNA and observed that it encodes a protein product nearly identical to its human homologue and shares an active site consensus sequence with Family 31 glucosidases. Amino acid sequencing of the 80-kDa protein, followed by molecular cloning, revealed high homology to human and bovine cDNAs postulated to encode the ␤-subunit of glucosidase II. Antisera developed to the mouse ␤-subunit allowed us to demonstrate that the interaction between CD45 and glucosidase II can be reconstituted in vitro in an endoglycosidase H-sensitive manner. The strong interaction between glucosidase II and CD45 may provide a paradigm for investigating novel aspects of the biology of these proteins.CD45 is a high molecular mass (ϳ180-ϳ220 kDa) transmembrane protein-tyrosine phosphatase (PTP) 1 expressed in abundance on all cells of hematopoietic lineage (1). Although CD45 is encoded by a single gene, alternative splicing of the mRNA allows for the generation of at least eight distinct isoforms of the molecule based on variable usage of exons 4 -6, which encode a region of the amino-terminal ectodomain. Of particular interest, and experimental utility, is the observation that these isoforms are expressed in a cell type-specific and differentiation stage-specific manner. The variable exon repertoire expressed by different isoforms is known to greatly influence the charge properties of CD45 since the region encoded by these exons contains multiple sites for O-linked glycosylation (2). CD45 also possesses 11-18 putative N-linked glycosylation sites, which are subject to cell-specific controls, conferring further microheterogeneity upon CD45 (3). It has been estimated that approximately one third of the total molecular weight of mature CD45 is contributed by carbohydrates, which vary qualitatively and quantitatively depending on the particular cell and isoform(s) expressed (3).The cytoplasmic domain of CD45 is identical among all isoforms and encodes two tandem PTP domains, at least one of which possesses intrinsic activity (1). A series of studies in CD45-deficient cell lines (1) and, more recently, in CD45 genedisrupted mice (4, 5) have revealed that CD45 functions as a key regulator of maturation and activation pathways in lymphocytes. One mechanism through which CD45 appears to function is by regulating the activity of various members of the Src family of protein-tyrosine kinases (1). Despite the advances that have been made, questions remain regarding many aspects of the biology of CD45. For example, it is not known whether certain, as yet unidentified, factors are responsible for...

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Isolation of cDNAs encoding a substrate for protein kinase C: Nucleotide sequence and chromosomal mapping of the gene for a human 80K protein

Cited by 65 publications

References 23 publications

Regulation of TRPV5 and TRPV6 by associated proteins

Regulation of TRPV5 and TRPV6 by associated proteins

Characterization of a murine β1‐4galactosyltransferase expressed in COS‐1 cells

Identification of the CD45-associated 116-kDa and 80-kDa Proteins as the α- and β-Subunits of α-Glucosidase II

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