scholarly journals The cyclin-dependent kinase inhibitor p57kip2 is a negative regulator of Schwann cell differentiation and in vitro myelination

2008 ◽  
Vol 105 (25) ◽  
pp. 8748-8753 ◽  
Author(s):  
A. Heinen ◽  
D. Kremer ◽  
P. Gottle ◽  
F. Kruse ◽  
B. Hasse ◽  
...  
2011 ◽  
Vol 30 (3) ◽  
pp. 889-897 ◽  
Author(s):  
Xiangrui Liu ◽  
Frankie Lam ◽  
Shenhua Shi ◽  
Peter M. Fischer ◽  
Shudong Wang

2007 ◽  
Vol 27 (9) ◽  
pp. 3530-3541 ◽  
Author(s):  
Jun Zhan ◽  
John B. Easton ◽  
Shile Huang ◽  
Ashutosh Mishra ◽  
Limin Xiao ◽  
...  

ABSTRACT The cyclin-dependent kinase inhibitor p21Cip1 regulates multiple cellular functions and protects cells from genotoxic and other cellular stresses. Activation of apoptosis signal-regulating kinase 1 (ASK1) induced by inhibition of mTOR signaling leads to sustained phospho-c-Jun that is suppressed in cells with functional p53 or by forced expression of p21Cip1. Here we show that small deletions of p21Cip1 around S98 abrogate its association with ASK1 but do not affect binding to Cdk1, hence distinguishing between the cell cycle-regulating functions of p21Cip1 and its ability to suppress activation of the ASK1/Jun N-terminal protein kinase (JNK) pathway. p21Cip1 is phosphorylated in vitro by both ASK1 and JNK1 at S98. In vivo phosphorylation of p21Cip1, predominantly carried out by ASK1, is associated with binding to ASK1 and inactivation of ASK1 kinase function. Binding of p21Cip1 to ASK1 requires ASK1 kinase function and may involve phosphorylation of S98.


2010 ◽  
Vol 22 (1) ◽  
pp. 329
Author(s):  
C. L. V. Leal ◽  
S. Mamo ◽  
T. Fair ◽  
P. Lonergan

Once removed from the follicle, mammalian oocytes resume meiosis spontaneously and progress through breakdown of the germinal vesicle to the matured state at metaphase II. The ability to reversibly inhibit such meiotic resumption has been reported and is a potentially useful method for studying developmental competence acquisition in oocytes as well as in some cases allowing flexibility in an IVF system where oocytes are collected from distant locations or on different days. The aim of the present study was to determine the effect of temporary inhibition of meiotic resumption using the cyclin-dependent kinase inhibitor butyrolactone I (BLI) on gene expression in bovine oocytes. Immature bovine oocytes were recovered from the ovaries of slaughtered heifers at a commercial abattoir and assigned to 1 of 4 groups: (1) Control: immature oocytes were collected either immediately or (2) after IVM for 24 h in TCM-199 containing 10 ng mL-1 EGF and 10% (v/v) FCS, (3) Inhibited oocytes collected either 24 h after incubation in the presence of 100 μM BLI in TCM-199 with 3 mg mL-1 BSA or (4) after meiotic inhibition for 24 h followed by in vitro maturation. All cultures were carried out at 38.5°C under 5% CO2 in air and maximum humidity. For mRNA relative abundance analysis, cumulus cells were removed and pools of 10 denuded oocytes were snap frozen in liquid nitrogen and stored at -80°C until use. A total of 42 transcripts, previously reported to be related to cell cycle regulation and/or oocyte competence were evaluated by quantitative real time PCR. Differences in relative abundance were analyzed by ANOVA and Student’s t-test. The majority of transcripts were downregulated (P < 0.05) after IVM in control oocytes (23 out of 42) and the same pattern was observed in inhibited oocytes that were allowed to mature. Twelve transcripts remained stable (P > 0.05) after IVM in control oocytes; of these, only two (PTTG1 and INHBA) did not show the same pattern in inhibited and matured oocytes. Few genes (7) were upregulated after IVM in control oocytes (P < 0.05) and of these, three (PLAT1, RBP1, and INHBB) were not upregulated in inhibited oocytes after IVM. Inhibited oocytes showed similar levels of expression (P > 0.05) as immature control oocytes, except for two genes (LUM and INHBB), which were increased in these oocytes (P < 0.05). The expression profiles of cell cycle genes were mostly unaffected by the BLI treatment. The few genes affected were previously reported as competence-related and could be useful markers of oocyte competence following pretreatment. In conclusion, the changes occurring in transcript abundance during oocyte maturation in vitro were to a large extent mirrored following inhibition of meiotic resumption prior to IVM and subsequent release from inhibition and maturation. CLV Leal was supported by CNPq, Brazil (PDE 201487/2007-1); Supported by Science Foundation Ireland (07/SRC/B1156).


2015 ◽  
Vol 98 (3) ◽  
pp. 465-472 ◽  
Author(s):  
Daniela Cihalova ◽  
Martina Ceckova ◽  
Radim Kucera ◽  
Jiri Klimes ◽  
Frantisek Staud

1986 ◽  
Vol 8 (3) ◽  
pp. 182-196 ◽  
Author(s):  
A. Baron-Van Evercooren ◽  
A. Gansmüller ◽  
M. Gumpel ◽  
N. Baumann ◽  
H.K. Kleinman

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