{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,1]],"date-time":"2026-10-01T15:02:03Z","timestamp":1790866923019,"version":"4.1.0"},"reference-count":0,"publisher":"National Academy of Sciences","issue":"5","content-domain":{"domain":["www.pnas.org"],"crossmark-restriction":true},"short-container-title":["Proc. Natl. Acad. Sci. U.S.A."],"published-print":{"date-parts":[[1994,3]]},"abstract":"<jats:p>We have identified the nucleotide sequence of the\ncDNA encoding the human counterpart of the mouse gene Plk (polo-like kinase).\nThe sequence of the human gene, PLK, predicts a serine\/threonine kinase of 603\naa. Expression of PLK mRNA appeared to be strongly correlated with the mitotic\nactivity of cells. Resting peripheral lymphocytes did not express the gene at\nall. When primary T cells were activated by phytohemagglutinin, a high level of\nPLK transcripts resulted within 2-3 days. In some cases, addition of interleukin\n2 to these cells increased the expression of PLK mRNA further. In contrast,\nprimary cultures of human peripheral macrophages, which were not dividing under\nthe culture conditions applied, showed very little or no PLK mRNA. Stimulation\nof these cells by bacterial lipopolysaccharide, an inducer of several cytokines\nin macrophages, totally abrogated the expression of PLK mRNA. In line with a\nfunction of PLK mRNA expression in mitotically active cells is our finding that\nsix immortalized cell lines examined expressed the gene. In A-431 epidermoid\ncarcinoma cells this expression was down-regulated by serum starvation and\nenhanced after serum was added again. Tumors of various origin (lung, colon,\nstomach, smooth muscle, and esophagus as well as non-Hodgkin lymphomas)\nexpressed high levels of PLK transcripts in about 80% of the samples studied,\nwhereas PLK mRNA was absent in surrounding tissue, except for colon. The only\nnormal tissues where PLK mRNA expression was observed were colon and placenta,\nboth known to be mitotically active. No PLK transcripts were found in normal\nadult lung, brain, heart, liver, kidney, skeletal muscle, and pancreas. In\nNorthern blot experiments with RNA from lymphocytes which were treated with\nphytohemagglutinin and cycloheximide, PLK transcripts were not detectable,\nsuggesting that PLK is not an early growth-response gene.<\/jats:p>","DOI":"10.1073\/pnas.91.5.1736","type":"journal-article","created":{"date-parts":[[2006,5,31]],"date-time":"2006-05-31T09:05:56Z","timestamp":1149066356000},"page":"1736-1740","update-policy":"https:\/\/doi.org\/10.1073\/pnas.cm10313","source":"Crossref","is-referenced-by-count":231,"title":["Induction and down-regulation of PLK, a humanserine\/threonine kinase expressed in proliferating cells andtumors."],"prefix":"10.1073","volume":"91","author":[{"given":"U","family":"Holtrich","sequence":"first","affiliation":[{"name":"Chemotherapeutisches Forschungsinstitut,\rGeorg-Speyer-Haus, Frankfurt, Germany."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"G","family":"Wolf","sequence":"additional","affiliation":[{"name":"Chemotherapeutisches Forschungsinstitut,\rGeorg-Speyer-Haus, Frankfurt, Germany."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"A","family":"Br\u00e4uninger","sequence":"additional","affiliation":[{"name":"Chemotherapeutisches Forschungsinstitut,\rGeorg-Speyer-Haus, Frankfurt, Germany."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"T","family":"Karn","sequence":"additional","affiliation":[{"name":"Chemotherapeutisches Forschungsinstitut,\rGeorg-Speyer-Haus, Frankfurt, Germany."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"B","family":"B\u00f6hme","sequence":"additional","affiliation":[{"name":"Chemotherapeutisches Forschungsinstitut,\rGeorg-Speyer-Haus, Frankfurt, Germany."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"H","family":"R\u00fcbsamen-Waigmann","sequence":"additional","affiliation":[{"name":"Chemotherapeutisches Forschungsinstitut,\rGeorg-Speyer-Haus, Frankfurt, Germany."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"K","family":"Strebhardt","sequence":"additional","affiliation":[{"name":"Chemotherapeutisches Forschungsinstitut,\rGeorg-Speyer-Haus, Frankfurt, Germany."}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"341","published-online":{"date-parts":[[1994,3]]},"container-title":["Proceedings of the National Academy of Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pnas.org\/doi\/pdf\/10.1073\/pnas.91.5.1736","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,4,13]],"date-time":"2022-04-13T14:05:16Z","timestamp":1649858716000},"score":1,"resource":{"primary":{"URL":"https:\/\/pnas.org\/doi\/full\/10.1073\/pnas.91.5.1736"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1994,3]]},"references-count":0,"journal-issue":{"issue":"5","published-print":{"date-parts":[[1994,3]]}},"alternative-id":["10.1073\/pnas.91.5.1736"],"URL":"https:\/\/doi.org\/10.1073\/pnas.91.5.1736","relation":{},"ISSN":["0027-8424","1091-6490"],"issn-type":[{"value":"0027-8424","type":"print"},{"value":"1091-6490","type":"electronic"}],"subject":[],"published":{"date-parts":[[1994,3]]},"assertion":[{"value":"1994-03-01","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}