Recent work utilizing the cell cycle specific protein kinase (nimA) of Aspergillus nidulans has lead to the formulation of a model to describe the regulation of mitosis in this species (Osmani et at., 1988b). The model proposes that cell cycle specific expression of nimA drives the mitotic cycle. This proposal is aimed at testing and expanding this model and at establishing to what extent the model is applicable to other systems. We will complete the molecular characterization of the nimA gene by sequencing the wild type genomic locus of nimA and obtain the sequence of the mutant alleles of this gene. These data will be required for subsequent manipulations of the gene and identify important residues in the nimA protein responsible for temperature sensitivity. We intend to carry out in vitro mutagenesis to modify the catalytic protein kinase site of the nimA gene and test its functional significance by introducing the mutated gene back into Aspergillus such that a functional analysis can be carried out in vivo. This approach will establish the importance of the protein kinase potential of the nimA gene. As cell cycle specific expression of nimA has been proposed to drive the mitotic cycle we will determine at what level the cell cycle specific expression of nimA is under control. These experiments will also ascertain the functional importance of cell cycle specific expression of nimA and determine if negative translational control is mediated by the 5' small open reading frames found in the nimA mRNA. Antibodies to the nimA protein are to be elicited and affinity purified and used to reveal the degree of conservation of the nimA protein in other eukaryotes. The antibodies will also be used to establish the sub-cellular location of the protein, to study the cell cycle specific variation in nimA protein abundance and protein kinase catalytic capacity, and to immunoprecipitate proteins associated with nimA protein. We intend to purify nimA protein from strains of Aspergillus that overexpress the nimA protein. The purified nimA protein and nimA specific antisera are to be used to establish the relationship between nimA and maturation promotion factor (MPF) by micro injection experiments in Xenopus oocytes.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM042564-03
Application #
3301221
Study Section
Cellular Biology and Physiology Subcommittee 1 (CBY)
Project Start
1989-07-01
Project End
1992-06-30
Budget Start
1991-07-01
Budget End
1992-06-30
Support Year
3
Fiscal Year
1991
Total Cost
Indirect Cost
Name
Baylor College of Medicine
Department
Type
Schools of Medicine
DUNS #
074615394
City
Houston
State
TX
Country
United States
Zip Code
77030
Suresh, Subbulakshmi; Markossian, Sarine; Osmani, Aysha H et al. (2017) Mitotic nuclear pore complex segregation involves Nup2 in Aspergillus nidulans. J Cell Biol 216:2813-2826
Shukla, Nandini; Osmani, Aysha H; Osmani, Stephen A (2017) Microtubules are reversibly depolymerized in response to changing gaseous microenvironments within Aspergillus nidulans biofilms. Mol Biol Cell 28:634-644
Chemudupati, Mahesh; Osmani, Aysha H; Osmani, Stephen A (2016) A mitotic nuclear envelope tether for Gle1 also impacts nuclear and nucleolar architecture. Mol Biol Cell :
Markossian, Sarine; Suresh, Subbulakshmi; Osmani, Aysha H et al. (2015) Nup2 requires a highly divergent partner, NupA, to fulfill functions at nuclear pore complexes and the mitotic chromatin region. Mol Biol Cell 26:605-21
Liu, Hui-Lin; Osmani, Aysha H; Osmani, Stephen A (2015) The Inner Nuclear Membrane Protein Src1 Is Required for Stable Post-Mitotic Progression into G1 in Aspergillus nidulans. PLoS One 10:e0132489
Larson, Jennifer R; Facemyer, Eric M; Shen, Kuo-Fang et al. (2014) Insights into dynamic mitotic chromatin organization through the NIMA kinase suppressor SonC, a chromatin-associated protein involved in the DNA damage response. Genetics 196:177-95
Govindaraghavan, Meera; Lad, Alisha A; Osmani, Stephen A (2014) The NIMA kinase is required to execute stage-specific mitotic functions after initiation of mitosis. Eukaryot Cell 13:99-109
De Souza, Colin P; Hashmi, Shahr B; Osmani, Aysha H et al. (2014) Application of a new dual localization-affinity purification tag reveals novel aspects of protein kinase biology in Aspergillus nidulans. PLoS One 9:e90911
Govindaraghavan, Meera; Anglin, Sarah Lea; Osmani, Aysha H et al. (2014) The Set1/COMPASS histone H3 methyltransferase helps regulate mitosis with the CDK1 and NIMA mitotic kinases in Aspergillus nidulans. Genetics 197:1225-36
Govindaraghavan, Meera; McGuire Anglin, Sarah Lea; Shen, Kuo-Fang et al. (2014) Identification of interphase functions for the NIMA kinase involving microtubules and the ESCRT pathway. PLoS Genet 10:e1004248

Showing the most recent 10 out of 67 publications