MAP kinase-like activity in transformed Catharanthus roseus hairy roots varies with culture conditions such as temperature and hypo-osmotic shock.
Mitogen activated protein (MAP) kinase-like activity was determined in extracts obtained from transformed Catharanthus roseus hairy roots by the ability to phosphorylate myelin basic protein (MBP). Both in solution and in gel kinase assays showed variation in activity, depending on root developmental stage. In gel kinase assays, using the extract soluble fraction, revealed a 56 kDa polypeptide with phosphorylation activity on MBP. In addition, another 75 kDa polypeptide was observed in the particulate fraction. Immunodetection with monoclonal antibodies against ERK-1, a mammalian MAP kinase, and with anti-phosphotyrosine antibodies cross-reacted with the 56 kDa polypeptide, named SMK56, from the soluble fraction, suggesting that this polypeptide could be related with members of the MAP kinase family. Antibodies against the dually phosphorylated threonine-tyrosine motif, characteristic of active forms of MAP kinases, also cross-reacted with this 56 kDa polypeptide. Changes in the levels of SMK56 were detected within the first 30 min of root exposure to low temperatures or hypo-osmotic shock, suggesting that this protein may be involved in the perception of environmental changes.
Islas-Flores
Ignacio
I
Unidad de Bioquímica y Biología Molecular de Plantas, Centro de Investigación Científica de Yucatán, Calle 43 #130, Col. Chuburná de Hidalgo, Mérida, Yucatán 97200, Mexico. islasign@cicy.mx
Zúñiga-Aguilar
José J
JJ
Rodríguez-Zapata
Luis C
LC
Carrillo-Pech
Mildred
M
Baízabal-Aguirre
Victor M
VM
Minero-García
Yereni
Y
Hernández-Sotomayor
S M
SM
D000222:Adaptation, Physiological; D020816:Amino Acid Motifs; D030008:Catharanthus / Q000201:enzymology* / Q000254:growth & development / Q000502:physiology; D003470:Culture Media / Q000737:chemistry; D046508:Culture Techniques / Q000379:methods; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D008970:Molecular Weight; D004676:Myelin Basic Protein / Q000378:metabolism; D009994:Osmolar Concentration; D009997:Osmotic Pressure; D010455:Peptides / Q000737:chemistry / Q000378:metabolism*; D010766:Phosphorylation; D018517:Plant Roots / Q000201:enzymology / Q000254:growth & development; D011233:Precipitin Tests; D013696:Temperature; D013912:Threonine / Q000378:metabolism; D013997:Time Factors; D014443:Tyrosine / Q000378:metabolism
D003470:Culture Media; D004676:Myelin Basic Protein; D010455:Peptides; D013912:Threonine; D014443:Tyrosine; D020928:Mitogen-Activated Protein Kinases