Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.16.2 (PCP)
 3,761 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Phencyclidine (PCP) is an illicit drug with a high potential for negative effects. It is easy to synthesize and difficult to control because the precursors are easy to obtain. DAWN data shows that PCP episodes in emergency rooms and hospitals have increased from the twenty-third most frequently observed drug in 1973 to sixteenth in 1975. One explanation for the increase in PCP use is the change in the mode of administration from pill to smoking. An exploratory study of a local outbreak of PCP describes the effects of PCP and the dilemma facing the user. Regular PCP use is difficult to hide, but since stigma is attached to PCP use, the PCP user is reluctant to admit to regular use.
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PMID:Phencyclidine (PCP): a local and national perspective. 61 89

We describe the cloning and characterization of PCP, a novel calcium-binding protein that is expressed predominantly in the pistils and anthers of Brassica flowers late in flower development. A PCP cDNA - isolated from a subtracted cDNA library enriched in transcripts present in the pistil late in flower development - potentially encodes a 175 amino acid protein with a calculated molecular weight of 19.1 kDa. Other than limited homology to a repetitive C-terminal polyacidic region of PCP, none of the sequences in the GenBank database shares identity to PCP. This unique protein was purified from an Escherichia coli expression system and shown to bind calcium in a specific manner, both in a protein blot assay and by equilibrium dialysis. PCP binds 29 mol of calcium per mol of PCP protein with an apparent affinity constant of 3.2 x 10(2)/M, values consistent with the presence of a high capacity/low-affinity calcium-binding domain. PCP-specific mRNAs are detected predominantly in the stigma and style of pistils excised from open flowers; much lower levels of expression are seen in anthers of open flowers and in root and leaf tissue. Expression in the pistil steadily increases during flower development and peaks at flower opening. A PCP-specific antibody first detects the protein in pistils at one day prior to flowering, with higher levels of the protein seen in the pistils of open flowers. A low level of the protein is present in anthers of open flowers; however, PCP is not detected in either root or leaf extracts. The pattern of PCP expression is consistent with a possible role for PCP in pollen-pistil interactions or in pistil development. The results are also discussed in light of the central role calcium maintains in pollen tube growth and fertilization.
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PMID:A novel calcium-binding protein is expressed in Brassica pistils and anthers late in flower development. 1035 87

In Brassica, two self-incompatibility genes, encoding SLG (S locus glycoprotein) and SRK (S-receptor kinase), are located at the S locus and expressed in the stigma. Recent molecular analysis has revealed that the S locus is highly polymorphic and contains several genes, i.e., SLG, SRK, the as-yet-unidentified pollen S gene(s), and other linked genes. In the present study, we searched for expressed sequences in a 76-kb SLG/SRK region of the S(9) haplotype of Brassica campestris (syn. rapa) and identified 10 genes in addition to the four previously identified (SLG(9), SRK(9), SAE1, and SLL2) in this haplotype. This gene density (1 gene/5.4 kb) suggests that the S locus is embedded in a gene-rich region of the genome. The average G + C content in this region is 32.6%. An En/Spm-type transposon-like element was found downstream of SLG(9). Among the genes we identified that had not previously been found to be linked to the S locus were genes encoding a small cysteine-rich protein, a J-domain protein, and an antisilencing protein (ASF1) homologue. The small cysteine-rich protein was similar to a pollen coat protein, named PCP-A1, which had previously been shown to bind SLG.
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PMID:Genomic organization of the S locus: Identification and characterization of genes in SLG/SRK region of S(9) haplotype of Brassica campestris (syn. rapa). 1047 21

Many flowering plants possess self-incompatibility (SI) systems that prevent inbreeding. In Brassica, SI is controlled by a single polymorphic locus, the S locus. Two highly polymorphic S locus genes, SLG (S locus glycoprotein) and SRK (S receptor kinase), have been identified, both of which are expressed predominantly in the stigmatic papillar cell. We have shown recently that SRK is the determinant of the S haplotype specificity of the stigma. SRK is thought to serve as a receptor for a pollen ligand, which presumably is encoded by another polymorphic gene at the S locus. We previously have identified an S locus gene, SP11 (S locus protein 11), of the S(9) haplotype of Brassica campestris and proposed that it potentially encodes the pollen ligand. SP11 is a novel member of the PCP (pollen coat protein) family of proteins, some members of which have been shown to interact with SLG. In this work, we identified the SP11 gene from three additional S haplotypes and further characterized the gene. We found that (i) SP11 showed an S haplotype-specific sequence polymorphism; (ii) SP11 was located in the immediate flanking region of the SRK gene of the four S haplotypes examined; (iii) SP11 was expressed in the tapetum of the anther, a site consistent with sporophytic control of Brassica SI; and (iv) recombinant SP11 of the S(9) haplotype applied to papillar cells of S(9) stigmas, but not of S(8) stigmas, elicited SI response, resulting in inhibition of hydration of cross-pollen. All these results taken together strongly suggest that SP11 is the pollen S determinant in SI.
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PMID:The pollen determinant of self-incompatibility in Brassica campestris. 1067 56