CELL TO CELL JUNCTIONS BY: ASHLEY COHN

SURFACE MARKERS STRUCTURE

VARIABLE,

INTEGRAL OR GLYCOLIPIDS

IN PLASMA MEMBRANE.

FUNCTION IDENTIFY THE

CELL

EXAMPLE MHC

COMPLEXES, BLOOD GROUPS,

ANTIBODIES

SEPTATE JUNCTIONS/ TIGHT JUNCTIONS

STRUCTURE TIGHTLY BONDED,

LEAK PROOF, FIBROUS CLAUDIN

PROTEIN THAT SEALS THE CELL

FUNCTION HOLDS CELL

TOGETHER SO THAT MATERIALS PASS THROUGH

BUT NOT BETWEEN THE CELLS

EXAMPLE JUNCTIONS BETWEEN

EPITHELIAL CELLS IN THE

GUT

ADHESIVE JUNCTION(DESMOSOME)

STRUCTURE VARIENT CADHERINS,

DESMOCOLLINS, BIND TO

INTERMEDIATE FILAMENTS OF

CYTOSKELETON

FUNCTION CREATES STRONG

FLEXIBLE CONNECTIONS

BETWEEN CELLS, FOUND IN

VERTEBRATES

EXAMPLE EPITHELIUM

• CADHERIN IS A PROTEIN WHICH IS A CA2+

DEPENDENT ADHESION MOLECULE WITH VERY WIDE POLYGENETIC DISTRIBUTION.

• DESMOSOMES ARE A CADHERIN BASED JUNCTION UNIQUE TO VERTEBRATES. THEY CONTAIN THE CADHERIN'S DESMOCOLLIN.

ADHESIVE JUNCTION ( ADHERENS JUNCTION)

STRUCTURE CLASSIC

ADHERINS BIND TO

MICROFILAMENTS OF

CYTOSKELETONS

FUNCTIONCONNECTS CELLS

TOGETHER, OLDEST FORM OF JUNCTION,

FOUND IN ALL MULTICELLULAR

ORGANISMS

EXAMPLE TISSUE WITH

HIGH MECHANICAL

STRESS SUCH AS THE SKIN

ADHESIVE JUNCTION(HEMIDESMOSOMES, FOCAL ADHESION)

STRUCTURE INTEGRIN

PROTEINS BINDS CELL TO

EXTRACELLULAR MATRIX

FUNCTION PROVIDE

ATTACHMENT TO A SUBSTRATE

EXAMPLE INVOLVED IN

CELL MOVEMENT AND IMPORTANT

DURING DEVELOPMENT

COMMUNICATING JUNCTION (GAP JUNCTION )

STRUCTURE SIX TRANSMEMBRANE

CONNEXON /PANNEXIN PROTEINS

CREATING A PORE THAT CONNECTS

CELLS

FUNCTION ALLOWS FOR PASSAGE OF

SMALL MOLECULES FROM CELLS TO

CELL IN A TISSUE

EXAMPLE EXCITABLE

TISSUE SUCH AS HEART MUSCLE

•PANNEXINS ARE PROTEIN FOUND IN INVERTEBRATES

•CONNEXONS ARE A PROTEIN IN VERTEBRATES

COMMUNICATING JUNCTION ( PLASMODESMATA)

STRUCTURE CYTOPLASMIC CONNECTIONS

BETWEEN GAPS IN CONJOINING PLANTS CELL

WALLS

FUNCTION COMMUNICATING

JUNCTIONS BETWEEN PLANT

CELLS

EXAMPLE PLANT TISSUE

•PLASMODESMATA IS CYTOPLASMIC CONNECTIONS THAT FORM ACROSS THE TOUCHING PLASMA MEMBRANES

ALL INFORMATION IN THIS POWER POINT CAN BE FOUND IN MGRAW HILL BIOLOGY 10TH

EDITION ON PAGES 83-85