Article #3 Summary

60 views3 pages
24 Dec 2010
School
Course
Professor
CSB428H1F Article #2: Benton et al. Drosophila PAR-1 and 14-3-3 inhibit Baz
Introduction
PAR-1 phosphorylates Baz on two conserved serines, which is then bound by 14-3-3. This inhibits
the Baz/Par-6/aPKC complex by preventing Baz oligomerization and binding to aPKC. This
excludes Baz complex at lateral sides and also Crb-sdt anchor Baz complex apically.
Baz lacking PAR-1 phosphorylation/14-3-3 binding side for ectopic lateral complex.
Drosophila follicular epithelium surrounds germline and side facing germline is apical.
14-3-3 and PAR-1 is required for epithelial polarization
par-1 null cells display uniform aPKC and other apical protein around the cortex.
14-3-3/leo null cells mostly die. survivors show uniform cortex distribution of apical aPKC, H-
spectrin and basolateral marker-spectrin.
A weaker leo mutant formed multiple layers of abnormal cells that failed to encapsulate germline.
Par-6/aPKC and H-spectrin was diffusely around entire cortex and formed abnormal aggregates.
In a 14-3-3/+;leo/leo double mutant, cells lose cuboidal shape and Baz, Patj, Arm is redistributed
along the lateral and basal membranes.
Show 14-3-3 is required as a cofactor for PAR-1 in epithelial tissue and act downstream of PAR-1.
Baz is a 14-3-3 binding protein
Yeast-two-hybrid show 14-3-3 binds Baz, since presumably yeast kinase phosphorylate Baz.
14-3-3 binding to Baz is not impaired by 14-3-3 mutation that impaired its binding to PAR-1, but
rather is abolished by phosphoserine mutation S151A and S1085A.
Yeast-two-hybrid of smaller fragments show two binding sites at N and C flanking 3 PDZ domains.
Serine is conserved and S950A mutation in C.elegans PAR-3 abolishes interaction with PAR-5.
PAR-1 directly binds and phosphorylate Baz
PAR-1 efficiently phosphorylated 14-3-3 binding sites on Baz in vitro and only C’ S1085 is
phosphorylated but not S1083 or S1084.
1
www.notesolution.com
Unlock document

This preview shows page 1 of the document.
Unlock all 3 pages and 3 million more documents.

Already have an account? Log in

Get OneClass Grade+

Unlimited access to all notes and study guides.

Grade+All Inclusive
$10 USD/m
You will be charged $120 USD upfront and auto renewed at the end of each cycle. You may cancel anytime under Payment Settings. For more information, see our Terms and Privacy.
Payments are encrypted using 256-bit SSL. Powered by Stripe.